How do I know when to end the bloom? I’m familiar with what the bloom is and why we do it. But all of the instructions and guides about pour-over coffee I’ve ever seen recommend a specific time to let the coffee bloom before continuing with the brew. 40-45 seconds seems to be the most common consensus.

But I have to assume that every coffee setup is going to be a little bit different. Small changes in the freshness of the beans, the size and shape of the grind, the temperature of the water, maybe even things like the mineral content of the water? - all of these factors and more are going to have at least some effect on how much CO2 the coffee wants to offgas and how long it takes. So, “45 seconds” seems like a good guideline or rule of thumb, but I would imagine that some brews need less time and some need more.

So, if I want to gauge my bloom time by my senses instead of by the clock, what should I look for? I have noticed that toward the end of the bloom, the coffee starts to make a faint crackling noise. As the bloom “falls”, it becomes flat, and then cracks begin to appear into the surface, and eventually it falls past flat and becomes a little bit concave. (When it’s flat and starting to crack it looks to me a little bit like a chocolate cookie. It makes me hungry in the morning.)

That’s what I’ve noticed so far about the “phases” of the bloom. At which point in the process is it best to begin the rest of the pour?

The bloom should be 30s for V60 and 40-45s for Chemex and Kalita and 30s for full immersion methods (like AeroPress or French Press). Blooming is not just about degassing but also to saturate the grounds (which obviously goes hand in hand) and to start dissolving solid compounds (mainly acids and caffeine, sugars come later).

If you'd want to change, just to see what happens (I doubt you will make better coffee with blooming times that diverge a lot from those "standards", since they have been proven to be optimal for the respective brewing devices used), then you could consider shortening the blooming time when the coffee is a few weeks old and has oxidized and degassed quite a bit. You notice when it stops bubbling, that would be a definite visual clue. If the same coffee that's been degassing until 30s (for V60), suddenly stops bubbling at 20s, you can try to reduce blooming time a bit. You'll run into trouble though, because your overall extraction time will likely be shorter until you figured out new grinder settings. The phases you describe really depend on the freshness of the coffee and the amount of CO2 it contains (darker roast would contain more e.g. because it's more porous). The slurry of very fresh coffee is still bubbly and has foam on top after 30s, not noticeably decreasing in volume, while a not so fresh coffee might fall flat after 15s already. I don't know what exactly you mean with cracks, I'll pay attention next time. More like holes where the CO2 exits, but I do agree it looks a little bit like chocolate cookies, when the coffee bed fell flat and the gas has mostly evaporated.

You can stir with a wooden spatula/spoon/chop stick to make sure you saturate all the grounds, but in my opinion that is not necessary and I've noticed that too much agitation somehow screws up the brewing, often over extracting. Which makes sense, more agitation, faster extraction. If you pour it nicely in concentric circles agitating the grounds slightly, you can manage to saturate all grounds without stirring and without agitating too much. That's ideal in my opinion, but the opinions on this point split widely.


What coffee and roast are best for Turkish? Following a stream of very good discussions about aspects of Turkish coffee preparation, here's a question about coffee selection.

Different brewing methods are thought to highlight different aspects of coffee aroma (e.g., darker roasts for espresso, but lighter for cold brew; see the discussion here). So often when you buy beans at a roastery, there is a recommendation regarding which methods are good for these beans & roast. Thus, a random bag of beans I'm looking at suggests they are good for batch-brew, aeropress, pourover and french press, but not for moka of espresso. But because Turkish isn't a big thing in many countries, it's never mentioned.

May uneducated impression is that Turkish preserves the acidity and keeps bitterness low. Do you guys know what its profile really is?
Alternatively, maybe there is a way to predict the suitability of particular
beans for Turkish based on its character compared to other methods. E.g., "beans good for aeropress will often be good for Turkish", or "Turkish is the opposite of espresso", etc.

I mean, I know when I like the coffee I made, so there are some favourites to my taste. But I can't disentangle the factors that contribute to my liking: is it the roast? the altitude? the mouthfeel? Which means I don't know what is more relevant, and this don't have properties to guide me in choosing new beans.

I believe the answer will be subjective. But, I can answer based on some tradition and history.

The coffee beans were originated from Yemen in Ottoman Empire. At least, Yemen was a hub. (This fact is even mentioned in folk songs. See here and here.) Historically, Robusta beans were not around, yet. Americas were not explored. So, if you want to follow the tradition, stick with African originated Arabica beans. Still, one should note that if you go for the current Turkish commercial ground coffee brands (like Mehmet Efendi, etc.) on the market, most of them include mostly Robusta beans from South America to keep the costs low. This is ugly face of horeca, I assume.

(African originated Arabicas are also my personal preference. My favorite is Ethiopian Harar. As far as I experienced, it is even better than Kopi Luwak for Turkish coffee. Also, this may be a hint. Kopi Luwak is known for low acidity. So, low acidity beans were not good for my taste even it was Kopi Luwak. On the other hand, Kopi Luwak was great while brewed with pressure.)

For roasting the beans, you generally do not need to burn the beans to eliminate the acidity. So, light roasts are OK for Turkish coffee. Majority of commercial brands prepare City roast and the minority prepare American roast (I think). If you taste burnt flavor in a package, it is clearly over roasted; you must be suspicious about the quality of the beans.

(My personal preference is a bit darker than that. City roast to full city roast.)

Last words: I think, as Turkish coffee is just a brewing method, it is up to the drinkers taste either to add sugar/gum/cinnamon/milk or not, either to use Robusta or Arabica, either to roast light or dark. I mean, if the drinkers find it more delicious, they can boil it up for hours (It exists!) before drinking. This is about the taste, so no boundaries. :)


What molds grow in brewed coffee? This question is not about molds that affect coffee plants. I am asking about molds that grow in coffee that has been sitting for a few days or more. I did not find any scientific articles on point so I have begun to try to answer the question by observing; but I may have missed an article and someone else may know the answer already.

Roasting probably kills any mold in coffee beans and if molds grow in a cup of brewed coffee they come from the surrounding air. After leaving many partially-filled cups in various spaces and looking at molds that grew in them, Aspergillus, Penicillium, and Aureobasidium are the only molds I have seen under the microscope so far.

If someone has seen an authoritative article about this it would interest me. Thanks. (This is not a health issue, IMO. I'm just curious.)

Though I don't have any articles on the matter, I can certainly say I've found cups of coffee that I had forgotten that are only maybe a week old with mold growing in them. I'd assume it gets contaminated so quickly, because of its sugar content. It might just be a coincidence, but it seems to happen more readily with coffee that I brew over ice. I press my areopress directly over ice, I've heard this reduces the acidity. Which would make sense, as acidity usually wards off mold. I leave all of my coffee black and unsweetened, so it is not dairy or added sugars that are causing this.

Perhaps try variating your brewing process. I'd be especially keen on the pH. Maybe there are some spores which will not grow in environments below a certain pH.


Water temperature for Aeropress: inverted vs tradional I was wondering why the aeropress directions call for water that is between 165~175 °F (73~79 °C)?

I always though that water should be between 195~205 °F (90~96 °C).

Also, I've read a few things and watched some videos that make me think if you are using the inverted method of brewing with the aeropress that your water should be hotter.

Does anybody have any experience or want to through their thoughts in on the subject?

This page on Angels' Cup has (see the middle of the page) a concise summary of the key variables and results in brewing coffee with a given method:

If it tastes sour: The problem is under extraction, so adjust brew time longer, or adjust water temp cooler, or adjust grind size finer.
If it tastes bitter: The problem is over extraction, so adjust brew time shorter, or adjust water temp hotter, or adjust grind size coarser.
Temperature affects the sour notes significantly more than the bitter notes.

  … you have to be willing to experiment. Don’t think of it as a waste of beans. Gulping coffee without paying attention to flavor is a waste, experimentation is the best possible use of good beans.

I've tried varying the grind size and water temperature in an AeroPress, and so far my results agree with this.

In particular, I've found that brewing medium roast beans with 175°F water (using a calibrated thermometer) produces coffee that's not sour, while higher temperature water often produces sour coffee (tasting a bit like vinegar). The company recommends 175°F except with light roast beans, in which case some people prefer 185°F water. See their FAQ about temperature.

I have not tried varying the brew time. The inverted method lets you increase the brew time but you can accomplish that without the mess by inserting the plunger, pulling back slightly to decrease the pressure below room pressure, then waiting.

You can see that the brewing variables are interdependent. That probably explains why people using the inverted method to brew longer would use hotter water to compensate for what would otherwise be over extraction. (I don't know why cooler water extracts more than hotter water.)

The ideal brew time, temperature, and grind size will vary with brew method. AeroPress immerses the grinds in water, thus it's relatively insensitive to grind size.


Is it possible to grind then roast? Is it possible to grind green coffee beans, then roast the grinds, and make a good cup of coffee with the result? Are there reasons why doing so would be impossible or impractical or would necessarily result in a bad cup of coffee? Has it ever been tried?

This is entirely a curiosity of mine, but I could imagine some benefits of making coffee in this way. For example, the roasting time may be much faster than traditional roasting, perhaps making the process of home-roasting more appealing.

No. Unroasted coffee beans are denser and wetter than roasted beans and will not grind well. You will break your grinder trying, and even if the grinder succeeded, you'd get more of a mush than solid grinds.

Also, roasting ground green coffee would allow much more of the oils and gasses trapped in the coffee to leak out during roasting than even the driest roast. The resulting coffee would taste strange.


Are there places in Belgium or netherlands where you can buy coffee green beans for agricultural reasons? I want to grow my own coffee tree from the seed in my home in Belgium but I can't find living coffee beans.

I went to a local coffee enterprise(Miko Turnhout) to ask for unburned seeds (green beans). They told me that their green beans are already neutralized(killed) so they don’t germinate during the transport. I looked online to buy green beans but I only could buy it in large amounts (min. 1kg) and it was very expensive because it had to travel from southern hemisphere.

Are there places in Belgium where you can buy coffee green beans for agricultural reasons? Or are there websites where you can order a small amount of coffee green beans without shipping them from the other side of the world?

For other people from Belgium or the netherlands who were searching for green coffee beans to farm. I found a website where you can buy them.

https://www.onszaden.nl/zoeken?s=koffie


Do I need to clean my drip brew coffee maker's filter every time? I remember days in the office that I was too busy to be bothered with rinsing the filter and just tapped it hard over a trash bin, do my best to get all the used ground out of there and brewed a new batch as usual. Is this okay, health-wise (surely flavour will be affected a bit) especially since I'm using it everyday, anyway?

Of course when I stop using my dripper for a while, there would be molds in the filter and that prompts me to soap and give it a hot bath.

Looks like a standard metal mesh reusable filter! The mesh is probably stainless steel, perhaps with a gold-tinted coating, sandwiched between a plastic frame. They're alternatives to paper filters for filter/drip coffee. I find the outcome to be a little gritty/grainy; more like French press than a regular paper filter.

In general, if your filter is still performing well, I think you're probably fine with a shake-out, rinse, or occasional scrub. However, any residue might impart off-tastes in your next brew (hopefully what's left is just coffee remnants!). The leftover coffee stuck to your filter (that you didn't wash off) will oxidise, taste stale, etc. (See also this question about coffee going stale -- one answer says it only takes minutes! And this question about what's happening with stale coffee.)

Wet coffee grounds will mould if allowed to sit too long as you report. So if you leave coffee in it, very wet, for a long time, you might be inviting flora and fauna that you don't want. You reported this in your question, but I'm surprised if it would happen very quickly. Clearly, when you have mould growing, you'll want to give it a good scrub. If you store your filter (grounds knocked out, even if not washed) in such a way that the filter can dry out more quickly (e.g., hanging, separate from the coffee maker, propped up to permit air flow, etc.) it seems that mould would have a harder time to grow.

As for getting clogged and occasionally needing a really thorough cleaning... I use a similar device for brewing tea, and it gets clogged sometimes. In fact, I wrote this question/answer on Cooking.SE recently about how it had become clogged after a decade of use; see that for more on how to get such a metal mesh really clean.

A probably-obvious alternative is to use a paper filter. You could toss the whole thing into your compost bin (filter and spent grounds and all!) and everything on the coffee maker will dry out more quickly.


Completely reusable, stainless-steel, zero-waste Nespresso pods any good? Getting ready to buy an inexpensive espresso setup for at work. I've been very happy with the EC155, but I've noticed that Nespresso machines are very well engineered, very inexpensive, and much smaller.

I will not use anything that has throwaway parts, and compostability claims are bogus, but I did find these (actually) zero-waste refillable pods:

here
here
here

Does anyone have experience or educated hypotheses about how well these would work?

TL;DR:
Depends if the coffee style matches the pod design.
How a Nespresso machine works:

pod put in the machine gets pierced on the upper side
hot water is released into the pod
pressure rises inside the pod
due to high pressure a membrane burst at the bottom of the pod
brewed coffee is released

By modifying the membrane to burst at a higher or lower pressure, other flavors will be extracted from the coffee, like pour over and espresso.


How do I know how hard to tamp my coffee? For someone without an expensive machine that can regulate the pressure when tamping, how can I know how hard to tamp, and if I'm tamping too hard?

I make espresso with a counter-top machine, and I tamp with a hand-held tamper like this:

Should I put my whole weight on it, or just a little? Does twisting while I tamp have an effect?

Each new bean becomes a bit of an experiment with each new machine you use.

A rule of thumb is to grind just enough to fill the portafilter so the beveled edge of the tamper becomes flush with the edge of the portafilter using about 15kg of pressure.

A crude diagram:

    ||||||     < Tamper
| [||||||||] | < Tamper 'head' flush with portafilter edge (note, it's flush)
| .......... | < Tamped coffee
| .......... |
+------------+
    /    \     < Goodness pours out here

But how much coffee that is, and just how much over 15kg you need to apply in order to tamp that much coffee to get the right pressure to pull a great shot is a matter of science that you'll need to do. You might want a finer grind instead of more pressure, you have to experiment.

Start with your usual espresso grind setting, a dose appropriate for the size of the filter you're using and then work from there.

You can get grinders that auto tamp for you based on your settings, so when you hit that 'eureka!' moment, you can reproduce it somewhat reliably using the same equipment. For home use? Just be ready to experiment with the first few filters full when you get beans you haven't tried before.

There's no real 'rule' here, other than you want as much coffee as you can get in the filter with the tamper sinking flush given about 15kg-ish of pressure. It varies wildly from there.


Avoid clumps in finely ground coffee I am currently using a Baratza Encore grinder with my Saeco Aroma espresso machine.  I know that neither of these are very high quality products, but I really don't have the budget to upgrade.  The Encore is able to grind sufficiently fine and I have been quite happy with it, however, I get a lot of clumping when grinding for espresso.  It can be difficult to evenly distribute the coffee when you get these clumps, so it would be nice if there was an easy way to avoid this.  Anyone have any suggestions?  I've heard people say that a doser can solve this problem as the rotating sections will break up the clumps.  This is a nice solution, but I don't believe the encore is capable of being upgraded to have a doser.

I wouldn't go so far as to say that it's not a very high-quality grinder, it does extremely well for the price. The clumping is an artifact of:

Humidity
Heat from grinding
Type and roast of the bean

Grinders that produce almost no heat while grinding, to the point that they do it reliably enough for it to be a listed feature cost ten times the amount that you paid for your grinder. Heat during grind isn't an indication of a low-quality grinder, rather, little to no heat is simply an indicator of a very high-quality grinder. There isn't much you can do about this other than purchase a manual burr grinder and grind by hand very gingerly, which takes lots of time.

Tamping alone should be sufficient to deal with any clumps (at approximately 15kg of force) - if it's not, then you want to take a very close look at the beans you're using, and the level of humidity they're exposed to in storage. Is your grinder normally close to anything that produces steam? Is your kitchen air really humid? Are the beans stored in air-tight containers? If you have clumps that tamping won't take care of, you probably have a moisture problem.

It can also be the bean, some roasts just do not do well for espresso, no matter how fine the grind or how dry the storage.

Both Lavazza and Illy produce a very pleasant medium arabica bean that should work very well in your grinder. They are very consistent in production, delicious, and should give you a good baseline to select other beans that would work similarly well. You can get beans that weren't specifically produced with espresso in mind to work, but it takes a bit of tinkering. I recommend the above beans very often to people just getting started because they're delicious and very easy to work with.

Anyway, try one of those, see what comes out of the grinder. If you're still getting clumps that don't immediately break down when you tamp (tap the portafilter on the sides a few times before you tamp to help this) you could try cleaning the grinder, changing how you store the beans, or looking at a de-humidifier in the area that you keep them.


Is there more caffeine with an AeroPress? I like everything about the AeroPress; however, I noticed that I exhibited symptoms which I usually only have when I've consumed too much caffeine.

So instead of using two scoops during preparation per instructions, I scaled down to one. That seemed to help, but not enough--if I use the same coffee and amount in a conventional coffeemaker and consume it all in one sitting, I don't feel over-stimulated.

Does the AeroPress simply make "stronger" coffee with regards to caffeine content?

Aeropress coffee (hearby called Aerpresso in this post) is more concentrated than regular drip coffee.  However, if you are using similar amounts of grounds as you would in a drip machine, you shouldn't notice any difference.  Caffeine is highly soluble in hot water and most any extraction method utilizing hot water will result in nearly full extraction of caffeine from grounds.

Aerpresso ends up somewhere in caffeine concentration between espresso (very concentrated) and drip coffee (less concentrated).  However, the total amount of caffeine is dependent more on the amount of grounds used that the extraction method (with the above listed methods).

So the the final answer is no.  There isn't more caffeine, but the Aerpresso is more concentrated.


What is going wrong with this Espresso shot? I am a coffee roaster and am working through building a standard espresso profile for coffee shops in my area.  I'm working with a particular shop that is interested in my coffee, but for some reason the espresso pulls extremely sour on their machine.  I'm looking for ideas as to what might be going on.  I've done quite a bit of research, so I'll add in what I have done thus far.

My Setup (Shots pull good)

18g grounds, pulling 2 fl oz with a final weight around 50g
Machine is a Rocket Apartamento, nearly brand new.  Water is filtered, non RO, boiler pressure is at 1.2-1.3 bar.
Grinder is a Breville Dose Control Pro, also new.
Shots are pulling in about 26-28 seconds

Results:

Espresso has good crema that stands up for longer than 1 minute and has rich orange / red tones.  Shot is lively, but not sour with no hint of bitterness, and good heavy body.  This isn't a fruit bomb blend or anything, I am more looking for something that a typical coffee shop customer would find palatable.  Espresso stands up to milk very well.  Personally, I almost feel like the roast may be slightly too dark since with milk, I start getting a hint of roasty-ness.

Shop Setup (Sour Shots)

18g grounds, pulling 36g output (supposedly this is 2 fl oz also, can't verify as I haven't seen markings on the glass they are pulling into.  If anything, I would say it is probably a 2.5-3oz pull)
Machine is A Nuevo Simonelli Aurelia 2.  Boiler pressure 1.4 bar, pump pressure 9.5 to 10 later in the pull. Water is not filtered to my knowledge.
Grinder is a used Mazzer, unknown burr wear (personally I'm thinking this is a likely culprit?)
Shots are timed for a 27-30 second pull.

Results:

Shots pull extremely bright / sour, crema tends to be closer to a dirty brown color.  This shot might blend with milk and be drinkable, but just barely.

Confusing points for me that may bear some explaination...

Longer pull (and thus probably a finer grind) results in sour coffee, not bitter.
Higher boiler pressure = higher water temp which tends to scorch if too high and impart more bitter qualities, yet this is sour.
Why is his 2 fl oz of extract such lower weight than my 2 fl oz.  Crema production is heavy on both machines, but the weight difference almost seems to indicate that the crema on his machine is double or more than what my machine is producing which isn't the case.

Troubleshooting espresso via web forum is pretty difficult but I would appreciate any thoughts on how I might go about getting good shots out of this shop machine.  Oh, btw, it wasn't me pulling the shots at the shop, so tamp could definitely be different between the two shots, but given that the pull times are pretty close together, and I did watch the tamp, I can say that technique is at the very minimum similar.  I can say that both tamps appear to at least be even on a naked portafilter.

I don't think anyone can really give a definitive answer to this but I'd like to chime in to try to help. It's almost impossible to find your answer because of how many different variables are at play here. You should first focus on minimising the variance in your methods.

You describe the shop shot as being a 'longer pull' and thereby expecting more bitter results. The problem with that assumption is that you can only truly compare shot times if you have extracted the same output weight in both cases. Since you have not, you have not only extracted much less in your shop shot, but, like you noted, it also took longer. I normally only ever measure my shots by weight because that's the number that tells me how much water got through and thereby how much real contact and subsequent extraction occurred.
I use time as a secondary reference to diagnose other problems in my shot. If I suddenly start extracting a same weight shot in half the time that I normally do, I know something is definitely off. Since your shop shot extracted much less output weight, the sourness is clearly due to some level of underextraction from being stopped too early (relative to your home shot). In any case, I always try to aim for 30g in 30s, which means you probably need to grind slightly finer in the shop to be able to extract more and try to hit the same balance as your home shot.
You mention your water sources being different. This is huge! You will never find the same shot if you are using filtered at home and unfiltered at the shop depending on how hard the water is when unfiltered.

Compare shot times as a secondary to consistent output weight and see how grinding finer in the shop would fare.

Higher boiler pressure does not necessarily point directly towards higher temperatures. Also, higher pressures could impact the puck suddenly when the valve is opened which could crack and cause channeling and therefore underextraction and sourness. Your main issues here are still in point 1.
Weight difference is purely by choice. Crema production is mostly dependent on freshness of beans and less to do with specifics in extraction method. If preset weight quantities are being used as part of a single button-press on a machine, then your problem starts there. You need to weigh every shot and choose when to stop the shot yourself. Without this control, you're simply relinquishing responsibility of the shot and you are at the mercy of the machine, yet another variable to consider in being able to find the right shot.

In conclusion, you MUST minimise variables. Make sure your grind sizes are the same at both locations, ensure your input and output weight are identical, analyse differences in taste and extraction time at same output weight, ensure your sources of water are identical, make sure your tamp pressures are the same. At this point the only real differences will be the machines and then you can start investigating how each machine is affecting the shots. Try to use bottomless portafilters in order to diagnose whether your distribution of your coffee bed was poor and whether channeling occurs during extraction.

Combine all of the parameters above with the taste of your output shots and you'll know the next steps you need to take in finding the problem in your shot.


What's the simplest/cheapest coffee maker that can make a good latte automatically? I would like to buy a machine that can make me a cup of good latte/cappuccino in the morning. There are dozens of options on the market: from capsule-based machines to huge expensive pro coffee makers, so it's very hard to choose.

What is the simplest/cheapest machine (in terms of long-term costs) that can make a good latte automatically? By 'automatically' I mean a system that delivers a cup of coffee with a press of a button, rather than having to skim milk separately.

I suggest you that do some research on superautomatic machines, there are plenty of options and we can discuss for years on which one is better (or worse).

You have to consider your budget I'll say. There are many machines, many brands, many functionalities, etc... But you'll never produce a great latte, because no machine (someone correct me please) can steam milk automatically with the consistency of a human barista. Most of automatic machines only froth the milk.

Maybe if you could present us more options or specify your constraints, we can be more useful.


opening a new unopened Starbuck's coffee bag is it possible to open a new Starbucks coffee bag by pulling the flaps apart,  I've never been able to do so ?

If you know of a way to separate the flaps by any other means without
causing a tear in the side of the bag, please let me know.

I always prefer to cut this type of bag open. There probably isn't TOO much chance of plastic ending up in your coffee grounds, but I feel better with a clean cut rather than the ragged ends.  Starbucks has top quality machinery, so their bags are always sealed very thoroughly, thus hard to open. With some other companies the heat seal on the bags is not as perfect, so the bags are easy to open.


Why does my moka pot sputter? I have an old 6-cup moka pot (bialetti) that I recently replaced the filter and the rubber gasket (bialetti brand), however the extraction time seems a bit long, bubbles to soon(almost immediately) and sputters out- resulting in that bitter over-extracted taste.  Strangely, it did work fine just a few times after I replaced the gasket but soon after the sputtering started. Thinking that maybe the rubber gasket was faulty, I replaced it again, but still the same problem. In the past, this moka pot has produced good brews with a nice uniform flow.

Could it be something is off with the safety valve i.e. not sealing enough and allowing pressure to escape?

By the way, I also have a 3-cup moka pot one that I have tested with the same process (pre-heating water, grind level, grind amount, medium heat) and the results are consistently good.

Folks - please be aware that there are at least two different thicknesses (not talking diameter) for Moka pots. I know that Bialetti makes gaskets in at least 2 different thicknesses.  If your Moka pot design needs a thicker one and the replacement is the thinner one, the seal will never be what it needs to be and the flow of coffee will be affected. Hope this helps.


How can I maximize the time the "high" lasts? I know it's individual, but in general (or at least, in average):

What are the main factors in how long does a coffee's "high" last? Can I deliberately make it last more than an hour? More than 3?

I would prefer to actually drink as less as possible, so please consider that.

If it makes it easier to answer: I'm 24, male, and my coffee intake is about one dose of espresso every other day.

Thanks.

Without considering the amount or potency of the coffee as well as setting personal metabolism aside, you could adjust your coffee schedule according to your natural circadian rhythm, a methodology neuroscientist Steve Miller refers to as chronopharmacology.  Essentially, you use the caffeine as a propellant to your natural "up" rhythm. Gabrielle Taylor's article does a fine job of explaining this:

When you drink coffee during the time when your body is already releasing cortisol, it won't have as strong an effect. Ideally, you want to get your caffeine during the lulls between cortisol spikes—otherwise, you start to develop a tolerance and have to drink more to get the same effect.
Assuming you're on a regular sleep schedule, your cortisol levels naturally spike about an hour after you wake up. If you get up at 7 am, your body is naturally most awake between 8 and 9 in the morning, noon to 1 pm, and again around 5:30-6:30 pm.
So, based on a wake time of 7 am, the best times to drink your caffeine vehicle of choice are 9:30-11:30 am and 1:30-5:00 pm. Obviously you can adjust the schedule according to your own wake time if it's earlier or later.


Keeping milk frother in shape We recently got new Milk Frother and I do not intend to it have residue which burns up as described in this question. What are ways to keep it clean after a day of use. I heard everytime you use it, wash it, if that is true just rinse will do or proper wash with fairy and sponge (which sound hectic) given In office.

For someone who works with high commercial grade espresso machines, I clean my shop's machine once a day before closing. There really isn't enough downtime in the day to deep clean the machine. For someone like yourself who might use it once or twice a day, just make sure that you always wipe it down with a damp rag and purge it a time or two for a couple seconds. If you really are concerned about it always being clean, buy some Cafiza. It'll keep your frother super clean.

Hope this helps!

https://www.webstaurantstore.com/urnex-12-esp12-20-20-oz-cafiza-espresso-machine-cleaning-powder/588ESP1220.html?utm_source=Google&utm_medium=cpc&utm_campaign=GoogleShopping&gclid=CjwKCAiAy-_iBRAaEiwAYhSlA89ztllMujcfFKnhSgahUDlT2wpWRh9g7gS37eHBVaF_3zyMx3GfJhoCvjIQAvD_BwE


What is coffee silver skin? A coffee chain states that its paper napkins are made of "coffee silver skin":

The explanation on the right says it is "coffee bean skin"---the husk.

Searching the internet about it, I can just find about silver skin in meat.

Is there more to know about "coffee silver skin"? For example, I wonder if all or part of the husk is part of it, and also why the term is "silver" (this could be a different question---please comment or ask it yourself).

Silver skin is the name generally used when it is still on the green beans.  This thin but tough layer is lightly colored (sometimes similarly to the paper product in your question) and mostly translucent.  It allows the green color of the bean underneath to be seen.  After roasting (when it begins to loosen and fall off) it is more properly called chaff.

Since the paper is likely made of chaff collected from the roasting process (easy to collect since nearly all roasters have a mechanism for separation) is actually an excellent reuse of chaff.  "Chaff paper" just doesn't have the same ring since generally chaff is thought to be a byproduct to be discarded.

The silver skin is the innermost layer of the coffee cherry surrounding the pit/seed (green coffee bean).  It is a tough substance to remove and different processing techniques remove varying amounts (dry process coffee removes the least and dry process coffee produces the most chaff when roasting).  Roasting the coffee both dries the silver skin and causes it to split as the coffee bean expands, so it comes off fairly easily during the roasting process given some agitation.


Simulated Vietnamese coffee in Bobba bars Vietnamese coffee is on the menu at most San Diego CA Bobba bars. They use freshly extracted espresso, but then, instead of sweetened condensed milk, they appear to use a combination of flavors like hazelnut and vanilla.

How would one approach changing a regular Vietnamese bubble coffee recipe into a flavored version?

A bubble tea (or in this case, coffee) drink consists of roughly these parts:

a liquid (in this case, coffee or espresso)
sugar and / or a flavoring ingredient
tapioca pearls
ice to dilute and chill it

In your case, the use of sweetened condensed milk make it “Vietnamese coffee”.

If you want to get some additional flavor into the drink, use the coffee shop staple flavor syrup - the same product that is used to flavor other espresso-based drinks. They should be readily available in your local supermarket (Monin being a well-known brand for example), online at the usual retailers, or your nearest coffee chain may be selling their own product. If you are so inclined, a websearch will also lead to lots of home-made recipes, especially for flavors like caramel or vanilla.

So how would a substitution work?
In short, you can either

use the syrup in addition to the sweetened condensed milk (will be extra sweet as you have two sugar sources)
use it instead of the sweetened condensed milk (if you are not interested in the milky component)
use it with unsweetened milk, condensed or regular, or coffee cream for the creamier mouthfeel.

For a large drink, a splash of syrup should be intense enough, although it depends a bit on the chosen brand. Start with a teaspoon or two, add more to your liking.


What reasonable diet substitutes for coffee cream are there? I need cream in my coffee. I can only stomach black, when it's excellent, properly brewed and so on. But at work I have no conditions for making excellent coffee - I make do with decent brand instant (lyophilized), I still need cream for it, and I need coffee to work.

And recently I went on a diet. I switched from sugar to stevia, and it's acceptable. But I still use cream for the coffee.

Obviously, the cream awfully cuts into my diet efficiency, so I'd like to switch it to some diet-compliant alternatives that will still make the coffee palatable, not a watered down slop, remain low-calorie and hopefully not cost an arm and a leg (even in spite of how rapidly would that reduce my weight) or require overseas shipping (to Poland).

What are my options?

I can relate to this. I often home roast, and always do pourovers, so I am used to great coffee. Pretty much the only time I put creamer/etc into coffee is bad coffee.

I've had good success with adding hot chocolate mix into bad coffee. You can get fake sugar versions of this, which are zero calorie (and come in convenient little packets), and they will make bad coffee considerably better.

Not sure about Poland, but I suspect you can find something similar there.


Caffeine vs Nicotine addiction We, who love coffee very much, have a belief that coffee(which has caffeine) is better than cigarette or any other products which has nicotine. But as far as I know caffeine isn't so good for the body too. Is caffeine is less harmful than nicotine? Is there any comparative analysis on this?

Here's a study where cocaine addicts were given IV nicotine or caffeine in comparable amounts:

https://www.ncbi.nlm.nih.gov/pubmed/11160635

Basically, both drugs showed roughly equal good/bad effects, patient liking, and stimulation, but nicotine caused most of the patients' heart rates to increase, while caffeine caused them to decrease. This particular article doesn't have much bearing on non-cocaine addicts, but it's the most reputable I could find that directly compared the two.

Most scientists agree that 1-3 cups of coffee a day isn't that bad for most people, especially if you take it black (no sugar, non-dairy substitutes, and other bad stuff).

http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20045678

On the other hand, nicotine, while possibly not terrible in small quantities on its own, tends to be packaged with serious health concerns (eg smoking


In home roasting, does the time spent roasting matter, or only the final temperature? I have a Fresh Roast SR500 home roaster and have had some success roasting mostly drinkable coffee.  My first attempts, following the instructions enclosed with the roaster turned out horribly, tasting both charred and grassy at the same time.  Yeechh.  After doing some online reading, I've greatly lengthened the roasting process with mostly good results.  I'm currently roasting batches of 90g of raw beans for between 12-17 minutes.  My thinking is that this is giving the beans time for the proper reactions to take place inside the beans without charring the outside.  But I've read that some commercial roasters might take 20 minutes or more to roast a batch.  Of course they are roasting much larger quantities than I am but it occurred to me that perhaps this longer roasting time is intentional and has some beneficial effect.

I'm mostly aiming for a City or City+ roast level and want to know if lengthening the roast time beyond what I'm currently doing is a good idea?  I would still stop the roast soon after First Crack, but I suppose I could stretch out the time to get there if that might produce a better product.

It does matter for a couple of reasons.

Drawing out the roast generally produces more even results.

Slower roasts mean that you have a better chance of stopping the roast at the target level and not over or under roasting.

You can search the online forums for some of the home roasting sites, but many people run their roasters at a higher setting, then turn down the heat once the roasting process is rolling.  Some of the more expensive machines even have "roast profiles" preprogrammed to modulate the temperature up and down for desired results.

Personally I think there is a point of diminishing returns between the time dinkering with the roaster and the difference in the taste.  Most of my roasting lands in the 15 to 16 minute range and comes out even enough that I feel good about it.  I recommend drawing the time out just enough that the results are even enough for you and you are comfortably hitting your target roast level the vast majority of the time.


What's the recommended coffee to water ratio for cold brew? I was interested today in making some cold brew. I have a french press so I'd like to use that.

What is your recommended brewing time?
Does this make a concentrate?
What ratio do you use later to dilute that concentrate?

First, make sure to study What do I need to start cold-brewing. But since concentrate is not discussed there, I don't think your question is a duplicate. Your French press concentrate could last a couple days, depending on the consumption.

Assuming you divide the volume of the French press by 5, you would need 1 part of ground coffee (the usual coarse grind you use in the press; extraction is weaker at low temperatures but the time makes up for it even with coarse grind) and 4 parts of fresh room-temperature water, which you gently mix and stir. The coffee should sit for about 12-16 hours at room temperature. Then plunge, and here is the concentrate. To dilute, use another 8 parts of cold water or milk (or better, start with 5-6 parts and taste to determine whether you want it still thinner).

Here's my favourite article that discusses dripping methods as well.


Distilled tasting coffee I'm wondering if anyone else has noticed that coffee can have a distilled water taste and if they do anything about it.

Coffee cannot taste like distilled water. It's not possible.

I think what you mean is that the coffee in question tastes too clean or too dry. That can be caused by using filtered water with too low dissolved solids or water with too high sodium content. The best water to use for brewing is generally thought to be hard water rich in magnesium and calcium, with no chlorine and low sodium content. If the dry, flat taste of coffee bothers you, try using mineral water, or, if you really want to experiment, buy water additive made specifically for making brewing water like Third Wave (you can find it on Amazon). You mix this additive with distilled water to create mineral water. You can also make your own water additive with 0.75g epsom salt and 0.36g baking soda per gallon of distilled water.

Water quality is very likely the problem if coffee consistently tastes flat, dry, or "clean". The only way to test this is to try the same brew with different water.


How to make lattes with plant milk I have just bought a VonChef Milk Frother. I am not sure if I am doing something wrong but the following happens when I put milk into the machine up to the maximum and press go:

Hemp - it just seems to heat to a lukewarm level
Rice - it doesn't froth the milk and heats to a lukewarm level
Coconut - it overflows after like 30 seconds with froth and the milk isn't warm enough

Are my dreams of preparing tasty rice milk lattes not going to happen or should I rather get a Nespresso Milk Frother?

You need a high-protein plant milk in order to obtain proper froth as the froth is kept in shape by what are essentially entangled protein molecules. According to google, rice milk only has ~10% of cow milk's protein, which explains why it doesn't work well. Soy milk has pretty much the same percentage of protein as cow milk, so that is worth a try. Coconut milk has ~70% of cow Milk's protein.

Regarding the heating: try a different setting of your frother. Heating should work the same no matter what milk you use.


Coffee passing through filter during bloom I have been making pour over coffee now for about 1 year. I enjoy it. I hand grind the beans with a burr grinder and select a medium-fine grind. What I find though is that during the bloom time (about 45 seconds), about 1 ounce of coffee filters through. Is that normal and expected, or is that too much coffee to be filtering through during the bloom time? Any suggestions?

The drip-through of water during the bloom process isn't itself a cause for worry of a 'bad' brew as this process is meant to aid degassing of the beans prior to the main brew pour. The amount of drip-through you're experiencing is completely fine as long as the entire bed of coffee has been wet by the bloom pour.

However, if you reckon there is too much coming through, make sure you're not using too much water relative to your total brew weight in the bloom. If a significant fraction of your water is used during the bloom, and therefore less being used during actual extraction, it will affect the resulting flavour.

I'd argue that as long as the amount of water used for the bloom is less than 1/4 of the total brew water weight and the entire bed is being wet by it, no matter how much filters through, it should not affect the brew significantly.


Coffee in bottom chamber of moka pot? I have recently purchased a new Bialetti moka pot and I've found that after brewing a cup of coffee and letting the pot cool down, there's coffee in the bottom chamber. Am I cutting off the heat too early? Or is this some kind of issue with the pot I'm using? Let me know what you think.

I think you are on the right track with your idea. To understand what's happening you need to understand how the moka pot works and how to correctly use it. I'll explain it here quickly but there are some nice illustrations on how it works on the Wikipedia entry for it.

First, the heat should be cut off once you hear the first hissing sound. That is when all the water has been pushed through the ground coffee and the brew is ready. By construction there remains a little bit of water in the bottom chamber. That is because the spout of the filter basket doesn't go all the way to the bottom of the chamber.

When the water starts boiling, the steam of the evaporated water pressurizes the chamber between 1,5 and max. 3 bar (that is the pressure the safety valve sustains without opening) depending on the grind size of your coffee, the amount of coffee and if you tamp it (which you should not). The gas pressurizes the area above the water, which pushes the water through the spout, through the ground coffee and into the top part until the water level is so low that the steam exits through the spout. That's the hissing sound. So one of two things could be happening here:

There might still be a lot of water in the "brewing chamber", where the ground coffee is, when you cut off the heat. Then the pressure in the bottom chamber will fall and the coffee in the middle gets sucked down into the water chamber.
Pretty similar but instead of the ready brewed coffee it is some of the grounds that get sucked into the water chamber and keep brewing there in the rest of the water. It may be that it is ground too finely.

Both of these things are not a problem though, just flush everything with warm water and that's it (no detergent if it's an aluminium pot or you risk oxidation).  It only affects the coffee if you cut the heat way too early or too late.


What's The Difference Between Paper and Long-Lasting Filters Lots of people use lots of filters for drip- or filter-brewed coffee. Some use paper and others use these durable filters. The performance to me is the same but many people argue that. They do have their pros and cons as said this website. So paper filters are easy to use and bad for the environment and long lasting filters last longer and are more environmental friendly... The site has somewhat decent amount of information, but not a lot of information.

What are the significant differences between long-lasting filters and paper filters for drip or filter coffee?

tl;dr: Permanent filters win on cost over time. Paper filters win on performance, clean-up, and health. Flavour is personal preference. Composting paper filters and spent grounds alleviates most of the environmental benefit of permanent filter.  My conclusion: paper filters, discarded into a compost pile, win hands down.

Use of permanent versus one-time-use filters is a perennial question, with both concrete and personal-preference arguments. In addition to the link in the original post, there are a few other online articles with comparisons, such as:

[1] pretty good pro/con overview from air-n-water (obscure?);
[2] from World of Caffeine;
[3] from LiveStrong, which advocates permanent filters (but has other statements with which I disagree);
[4] from Melitta, but this may need a grain of salt, because they're in the business of making paper filters :)

From those and my personal experience, I extracted an overview and conclusions, below. Unfortunately I've written a lot of text here, but there's a lot of facets. I've focused basically on paper versus metal mesh, as the most common types; I maintain the conclusions are similar regardless of material.

Material. There are several materials used for permanent filters, including the following:

metal mesh (stainless steel or "gold tone");
nylon (or other plastic) mesh;
perforated metal (thin metal sheet with holes);
fabric (e.g., flannel, muslin, hemp).

All of these surely have different properties, but properties that I focus on here are common to most.

One-time-use filters are predominantly paper, but could also be bamboo, natural fibre, or other material. See also this question for a comparison of brown versus white paper filters.

Performance. Paper filters are a finer filter; a permanent filter will permit some larger particles through to the cup. I find that a pot brewed with a permanent mesh filter will have a fine silt of coffee grounds at the bottom. For this same reason, some recommend to use a coarser grind for permanent filters.

Paper filters are also claimed to filter out some compounds (e.g., diterpenes such as cafestol, which may increase blood cholesterol levels). Coffee brewed by other (non-paper-filter) methods have a higher concentration of cafestol in the resulting beverage.  See article [2] for more health claims of paper filters. On the other hand [3] says that paper filters filter out some good things, such as antioxidants, but I haven't seen that claim anywhere else.

Flavour. Link number [4] claims better taste on paper filter than permanent filter (I happen to agree).  Permanent filters should also allow more oils to pass through, which will certainly have an impact on flavour; this is probably personal preference. The grit that passes through will also have a bittering effect over time, but probably not significant if you're drinking right away. Some (e.g., [1]) say nylon/plastic mesh will retain off-flavours over time.

Cost. Varies greatly, but one can find permanent filters that are said to last for "years" for a few quid ($/€/£) up to 20-30 quid. Though dependent on usage and other factors, you'll have reasonable expectation of saving money over time by using a permanent filter.

Clean-up. Clearly, the spent grounds from re-usable filters must be cleaned out; paper filters and their spent grounds can be pitched wholesale.  See another question about how often and how much to clean a permanent filter. On the other hand, [3] claims that permanent filters are cleaner, but I don't agree.

Waste / environmental issues. I couldn't find any data on how much energy is used to produce a paper filter versus a reusable filter, but many uses would certainly be necessary to break even! As far as waste volume though, you'll make up the difference with paper filters pretty quickly (but composting the paper instead alleviates this!). Cleaning permanent filters additionally requires water and detergent. Though, you may wish to rinse your paper filters, so water use is debatable. Ultimately, reusable filters will eventually wear out and need to be replaced.

My Conclusion. For my money, personally, I prefer the paper filter:

Better flavour and texture (less bitter, less grit);
Convenience (easier to use and keep clean);
I compost the whole thing (paper filter, grounds and all), so the environmental impact is basically on the production end, which I'm okay with.
Marginal health concerns (cafestol/cholesterol; avoiding plastic whenever possible).


Could preparation method make coffee more acidic? This is more of a vague feeling than something I'm sure of, but from the many cups I've drunk, I have a feeling that when prepared in a french press, my coffee tastes a little more sour/acidic, compared to a turkish brew. Is this a documented phenomenon, or is it just me?

Of course, assume the same coffee is used both times, which by the way is some home-ground (blade grinder) arabica.

This is a perfect follow up to the "What coffees are the least acidic?" question!

As always, Lets answer it with some data! My company uses machine learning, data science, and sensory science to build flavor profiling and quality control tools for the craft beverage industry.

TL;DR: Yes. Preparation has a significant affect on the flavor profile of coffee - including the level of acidity.

Distribution of Acidity by Brewing Method

If I may present to you... the distribution of acidity in coffee by brewing method!
Clearly and without surprise, Espresso (coffee extracted under pressure) is the most acidic preparation method, on average. French Press (full immersion brewing) is the least acidic, and V60 (a type of pour-over) has the widest range.

But is there something else going on here?
What if there exists a conflating factor such as green processing, roast level, or growing environment? Some of these questions we're already answered in the link above, so lets focused on the remaining question - how does the origin of the coffee effect the perceived acidity of the coffee by brewing method?

Acidity by Brewing Method Controlling for Continent of Origin

So is the effect of brewing method consistent? No.
What we're seeing here is that each continent tends towards a different green processing technique, and thus a different optimal level of roast - all of which exert as much influence over the resulting level of acidity in the flavor profile of the coffee.

Please just save me from exogenous variables

Oh... you should have just said so....

This is a conditional inference tree mapping the distribution of acidity scores to a series of categorical variables.

Where:
C is Country
P is Preparation
G is Green Processing
and the bar plot shows the distribution of acidity

Country is clearly the most used variable in creating this tree, and interestingly, Green Processing is only used as a splitting rule when a country has a variety of green processing methods in common use.

Please leave a comment if you'd like me to add a variable or further analysis to this answer!


Percolation vs Osmotic brewing method: is it the same thing? I have just learned a pour-over brewing method called "Osmotic Flow" as in the link below:
https://cafec-jp.com/brewing-guide/
The article said it used osmotic pressure to extract coffee essence from grounded coffee, as opposed to "full immersion" method.
To me, the osmotic method looks pretty much like a normal pour-over method (except pouring only at the center) in which we usually called it percolation method.
Can you please help explain how percolation and Osmotic are different? or it is just the same thing?
thanks.

What's strange is that the post you link to describes full immersion as falling under the category of 'pour-over techniques'. Typically it's more common to think of two categories, percolation and immersion. Percolation covers everything involving water being pushed through a bed of coffee - so low-pressure percolation would be something like a Chemex or V60 pour-over, and a high-pressure percolation could be something like espresso. Meanwhile, immersion brewing covers French presses, cold brew, cupping preparation, Turkish coffee etc. where the coffee grounds sit in some water for a while, and then we use some method - the mesh in a French press or the steady hand of someone preparing Turkish coffee - to separate the grounds after. Some brewing methods blur the line between these two categories, like the Aeropress or the Clever dripper, which immerse coffee grounds in water for a period of time, and then use some mechanism to percolate the water through the grounds. Given all this, describing a 'full immersion' brew as a type of pour-over method is... weird.
It seems like what the linked post describes as a 'full immersion' pour-over is essentially a bad or failed pour-over. In a pour-over, what we want to do is have a steady flow of water through the bed of coffee, and we use things like water temperature, brew time, grind size, grind dose, etc. to control the level of extraction in our brew. Too little extraction means a dull, boring cup of coffee; too much extraction can produce lots of bitterness or acidity or nasty flavours in the cup.
Sometimes in a pour-over brew, for whatever reason - perhaps the grinds were too fine and clogged the filter paper, or perhaps the filter stuck to the brewing vessel and created a vacuum - the brew will stall and fail to draw down like it normally would. This increases our brew time and can lead to over-extraction with lots of bitter notes - which the post describes as 'unpleasant taste components'. It seems like this 'Osmotic Flow' is basically a bunch of tips for avoiding a stalled pour-over brew: try not to disturb the bed of coffee too much with rapid or heavy pouring, use a bloom phase, pour in batches instead of all at once, and so on. All good tips - but certainly not a new brewing method.
In short, then: percolation is one of the two main families of brew methods, alongside immersion brewing. A sub-category of percolation are pour-over methods - things like the V60, Chemex, etc. This 'Osmotic Flow' method doesn't seem to be a method at all; instead, it's a set of tips for how to have a good pour-over and avoid the common problem of a stalled brew. Helpful - but not a new method!


I've burned my stainless steel macchinetta. Is it still safe for use? I accidentally put my macchinetta on the stove with no water in it. A few minutes have passed until I realized what I have done, and in the mean time the pot has overheated, started to smell quite badly, and it's bottom has received a (permanent?) brownish hue.

The pot is stainless steel (bialetti venus model), but I don't know what the inner coating is made of. In terms of toxicity, is it safe to continue using it?

Yes, it is perfectly okay to overheat stainless steel.

You can clean it by boiling soap water in it. Here's a link

You should replace the seal (the seal should be replaced ever so often anyways).


How does the temperature of the water affect the taste of the coffee Many methods of brewing coffee differ in the temperature of the water among other factors. Some people swear by cold-brewing, others do slow pour overs with piping hot water.

How exactly is coffee flavor changed by cold, warm, and hot water?

Temperature affects extraction rate, but also varies between compounds in the coffee beans.

Coffee grounds contain a hodgepodge of volatile and non-volatile components, such as various oils, acids, and other aromatic molecules [2]. Collectively, these compounds that are found in coffee grounds are referred to as “coffee solubles” and significantly contribute to coffee flavor [2]. Brewing is the process of extracting these components from the grounds, so coffee beverages are technically a solution of coffee solubles and water. Given that coffee grounds are used in both of our brewing methods, the principle variables are temperature and time.
Temperature affects the solubility and volatility of the coffee solubles. Relative to brewing, solubility describes the ability of the solubles to dissolve out of the grounds and into the water; volatility refers to their ability to evaporate into the air. Coffee solubles dissolve best at an optimal temperature of 195-205°F [3]. With more coffee solubles extracted, hot brew coffees are described as more full-bodied and flavorful when compared to cold brew. Moreover, due to increased volatility with higher temperatures, the aromatics are more readily released from coffee, giving rise to that beloved scent of freshly-brewed coffee.
On the downside, oxidation and degradation also occur more rapidly at higher temperatures. The oils in coffee solubles can oxidize more quickly at elevated temperatures, causing coffee to taste sour. Acids also degrade, the most notable of which is chlorogenic acid into quinic and caffeic acid, causing coffee to taste bitter [2].
Where cold brew lacks in temperature, it makes up for in time. Coffee solubles have markedly decreased solubility in room temperature water. Increasing the brew time from a few minutes to many hours aims to maximize extraction of the solubles from the grounds. Even over twenty-four hours, not all the coffee solubles will have dissolved; this is why the amount of coffee grounds is doubled, in an effort to make up for the lower extraction rate. In comparison with hot brew, cold brew is sometimes described as tasting “dead” or “flat” due to the lower yield of coffee solubles [3]. Further, decreased volatility prevents aromatics from escaping from coffee as easily, so cold brew is much less perfumed than its hot brew counterpart.
Oxidation and degradation will still occur in cold brew methods, but this happens much more slowly; bitterness and acidity are just about absent in cold brew coffee, especially if it is kept cold. Though, cold brew doesn’t merely taste like hot brew without the bitterness. Fans of the cold brew method have emphasized that cold brews contain a completely different flavor profile that can’t be found with hot brews. Going back to the idea of solubility, not all flavor compounds of coffee solubles are equally soluble. A good majority of the coffee solubles are still able to leach out of the grounds, even in colder water. The compounds that don’t dissolve are the ones often attributed to unfavorable flavors [4]: these stay in the grounds that are subsequently tossed away. Consequently, cold brews take on a much sweeter, floral profile.
To note, brew time does not determine caffeine content, nor does bitterness indicate coffee strength. Caffeine is extracted early in the brewing process, so extending brew time, by either method, would only result in over-extracted coffee [1]. Coffee “strength” is defined as the amount of dissolved coffee solubles per unit of coffee volume [1]. On that train of thought, cold brew certainly produces stronger coffee, given that the brewing process purposely concentrates the coffee solubles. Though, keep in mind that rarely anyone drinks cold brew coffee straight up; many enjoy this smooth drink diluted with milk or water. - Coffee Brewing Chemistry: Hot Brew vs. Cold Brew.


Waiting a few minutes or adding a little cold water immediately, do they make different tastes for instant coffee? I make instant coffee with hot water, and wait till it gets little colder. Or I can also add a bit cold water after the hot water.

The question is, Does it make different in the taste?

It is my understanding that the bitterness comes from coffee grinds in hot water for longer period of time or in really hot water above like 160f. The longer they are in hot water the more bitter it becomes.

So I would assume that leaving them in the hot water til it cools would have a more bitter taste, however I'm not clear on instant coffee, or how long it needs to steep. In fact it may be designed to work the way you use it.


How to properly use the Bialetti Brikka The Brikka, like many stovetop espresso makers, has a lot of parameters that affect how the espresso turns out.

What are the best parameters for using the Brikka correctly? Which of these are more vital to getting the crema to stick around once you pour the espresso into the cup?

My current list is:

Ground coffee particle size (compared to espresso machine fine or coarser)
Amount of water filled in the bottom part
Amount of coffee you put in the basket and compression - this one is supposed to be easy, fill it up without a hump and without pressing it down
The fire size and strength under the Brikka - I use the smallest flame base, but using the smallish 2-cup Brikka it is a bit bigger than the base when on maximal burn.
When exactly to turn off the fire under the Brikka
When exactly to pour the coffee (it says right after the coffee comes out, but there is coffee still coming out of the nozzle if I pour it too soon).

I understand that the crema created by the Brikka is an approximated crema using the gasket's small opening. Sure, purists may not consider this tan, smooth film of microbubbles as authentic crema (akin to espresso makers), but it does do a good job creating it for a close mouthfeel.

I use my Brikka every day, and it creates the "Brikkrema" (as I'd like to call it) just fine [see the photo].

If you aren't achieving proper results, it could be the water, or the bean you're using. I've had instances where some beans wouldn't generate a great crema, as compared to other varieties. Factors could be the age, the containers their kept in, and all basically relating to the oils and the CO2 trapped in the bean shortly after roasting.

The last photo shows a comparison between pours. The first pour (left) often providing the most crema from a brew, while the subsequent pours (right) may not have as much. It helps to spread the first pour over each shot if you have more than one shot to serve, and then pour the rest of the coffee along the side of the cup as not to disturb the cream on top. Sometimes, a brand new Brikka needs 3-4 brews before it begins creating its magic. But even so, if you aren't achieving your preferred result, try these tips:

Try to lessen the water below the water line

start with a shot's worth of water then see what you get, then just increase to get a proportion you're happy with).

Try filtered water

you'd be surprised how big a difference water quality can make.

Change the bean you're using, until you get your desired results.

Some beans offer varying levels of crema, whether it's because of the CO2 content from the roast or just the overall nature of the bean.

Good luck! And don't worry, at the end of the day it boils (or brews) down to personal preference.


Should I grind my coffee beans at home, or en masse in the coffee shop? I bought a pack of New Orleans' PJ's whole bean coffee. It is a bit old, about a year. I am flexible type though, I'll drink it.

The problem is my indecision about whether to grind it piecemeal or just all at once. I have a cuisinart machine that works quite well. But it's for a small amount.

Curious as to the best way to ensure somewhat fresh cups.

That's pretty straightforward: if you're not too lazy and have the equipment at hand, always grind only the amound needed just before brewing.

Check out this answer for impressive data.

Now if your beans are year old already, this might not make a huge difference --- but there's no way that grinding it all at once could help you have ``somewhat fresh cups''.


what is a good semi-automatic espresso machine for home? I used to own a coffee shop, and was a good barista for my shop and I really miss a nice cup of latte or mocha, would love to have a nice espresso machine at home that is semi-automatic with a steamer and takes coffee beans.

I prefer if it is on a low budget, la marzocco if possible, a cheap one that could be refurbished.

There are loads of best espresso machine buyers guides out there. 99% of them recommend the Breville Barista Express.

I'd prefer something with a little more manual intervention like the New Gaggia Classic to be honest.

Cheers


When does coffee go off? If I've ground a batch of coffee, I know I should use it as soon as possible, but if I store it (in an opaque, air-tight, slightly-below-room-temp container), how long have I got to use it? Are there any key points at which the quality will degrade (e.g. after a day, after a week)?

Whole Bean Coffee Degradation Over Time

Whole bean coffee will go stale within 14 days - on average. The graph below shows the quick 1.5 standard deviation drop in quality within the first 14 days (marked in red). *See note below for details

Staling in the context of coffee has a commonly agreed on definition - the loss of volatile aromatic compounds and the oxidation of surface oils on the roasted coffee beans. The loss of aromatics affects the flavor profile because: 1) they are both part of the same degradation process and 2) the majority of what you taste in coffee is flavors from volatile aromatics through retronasal olfactory sensation.

This graph was created using data from Analytical Flavor Systems where we build quality control and flavor profiling tools for craft beverage producers. Perceived Quality is a non-hedonic assessment of a product's quality. This time series is taken from a degradation study.

Ground coffee, on the other hand, will stale within minutes. 70 cc of ambient air is enough to render one pound of coffee stale. On average, this process takes seven minutes.

Interestingly, the degradation curve looks about the same!

Data Analysis Minutia (notes)

This time series model was segmented using daily Perceived Quality means from a random selection of 15,000 coffee reviews. All coffees included are whole bean, freshly ground, third wave coffee brewed in a Chemex with a bleached filter.

Certain other brewing methods, particularly methods optimized for older coffee such a Nel, may show a different degradation curve.

The staling point was selected by a parametric statistical change point analysis, which searches for shifts in the mean and variance of a time series. This time series was modeled for change point analysis using a Poisson distribution as  we're searching for the average number of coffees that go stale within a specific time-point, and the model was set to find at most one change.


US equivalent of SCAE? Europe has the SCAE (Specialty Coffee Association of Europe) which is a non-profit trade association and large community of coffee enthusiasts.  They also have established the "Coffee Diploma System" and host networking events.

In the UK, you're able to take courses towards a "SCAE Coffee Diploma". Is there an equivalent association in the US?  I've never seen a US standard for coffee training.

There is a Specialty Coffee Association of America, and they have a professional development program with certificates.  (Also various awards and recognition programs.)

I'd be surprised if there was not some formal parallel in the two trade associations. The SCAE's "about-us" page says: "Together with the Specialty Coffee Association of America (SCAA), we represent the speciality sector on the International Coffee Organization's Private Sector Consultative Board."

The SCAA Chronicle from Oct. 2010 carried a story about a joint venture with SCAE called World Coffee Events, to "develop and manage competitive events on behalf of both organizations."

Added: There is also a Specialty Coffee Association of Japan, established in 2003.  SCAE began in 1998, and SCAA in 1982.


Help me determine the strength of my coffee I drink coffee from a Nespresso Machine (Nespresso Pixie).

I use one capsule of Ristretto Italiano (black), but run it twice under the 'Lungo' option.

Thus my question is:
What is the strength of the cup I am getting (it'll be weaker than an espresso)? And what other brewing method can give me the same result? Moka pot? Drip coffee?

The Lungo option is a weaker setting and is still meant to be run ONCE. You run the Lungo option and use a coffee cup slightly larger than the Expresso cup. Nespresso is NOT meant to make a regular cup of coffee ever. It makes Expresso (40ml or 1.4 fluid ounces ounces) or Lungo (110ml or 3.7 fluid ounces). Also not all capsules can be used for Lungo since some are meant for weak Expressos. Get yourself a Coffee Press for regular coffee.

Another Option is make a Lungo and use Expresso to control strength of coffee. So one Lungo and 1 Express will make a medium strength small cup of coffee. Also certain brands like Bustelo capsules make very strong Expresso and Nice Lungo.


Should I thoroughly clean the portafilter basket between shots? When I'm making lots of individual drinks I tend to clean the portafilter basket thoroughly and then dry it before filling it again etc.

I've watched baristas and they tend to just knock the old coffee out and immediately refil the portafilter without cleaning. I'd have thought that this would create bitter coffee as the grounds will already have been through one extraction.

Is it accepted that you should clean the portafilter between shots, or is it ok to reuse?

There's a trade-off here. If you're working in a fast-paced coffee shop, you're likely to favour the faster option (knock out the coffee) over cleaning. Generally knocking out the coffee will get rid of >99% of the grounds from the previous pull, so the impact on the flavour of the next one will be so slight as to be unnoticeable. Usually the portafilter won't even have time to dry out, so the coffee won't dry on and clog up the portafilter.

If you're making multiple coffees one after another, reusing the portafilter is probably acceptable.

However if you're leaving the coffee machine alone, it's best to at least rinse out the portafilter before you (or the next person) comes to use it. Once the grounds/coffee start to dry, it'll clog up and be much harder to clean further down the line.


Will using teabags in a Keurig cause problems? Am I at risk of damaging my Keurig machine if I place an ordinary black tea bag inside instead of a K-Cup?

It will not damage the machine; However, it won't brew properly.  Your tea is supposed to steep inside the water for a set period of time; but the Keurig will simply pour water quickly through it, resulting in extremely weak tea.

So no, it won't damage the machine, but you will not brew your tea correctly.


How does coconut milk change the taste of coffee? My father bought coconut milk several days ago. So, I've been wondering: how does coconut milk change the taste of coffee?

Is there a coffee variant which would taste awesome with it?

I recently tried that (trying to make Bulletproof Coffee) with homemade coconut-milk and it's awesome.

The benefits on focusing are amazing (I'm a programmer & I really feel that) with coffee. I tried that with (normal) butter and another one just with (homemade) almond milk + coconut milk + drip coffee (Chemex)

I'm planning on buying some market coconut-oil, but it's too expensive. I really recommend it to you. Also if you blend it (to mix everything more consistent) it gives you a latte feel.


Is it true that drinking coffee can reduce your height? I've heard that drinking coffee can reduce your height. I've been avoiding coffee since last year.

You're going to shrink if, for no other reason, than the disks between your vertebrae compress. If you're worried about Osteoporosis then start lifting weights and make certain you have enough calcium, vitamin D and other bone healthy nutrients.

I've never seen anything correlating caffeine and height except for children (which is disputed).

Don't forget to cut out tea, colas, and chocolate as well.


Could you list healthy, unsweetened coffee flavouring syrups? Most of the coffee syrups sold by big chain cafes are either traditionally sweetened or artificially sweetened.  However, the flavoured coffee they have "on tap" are completely unsweetened, which is what I seek.  I've done some initial web scouting for syrups, but it's not always easy to ferrut out a complete ingredients list.  Though I have come across lists such as "other ingredients" below the nutrition table.  Not too sure how to interpret that, as I do not view the nutritional table as an ingredients list at all.  Many syrups are general-purpose rather than being meant for coffee.

Rather than continue running down what seems like a high ratio of information dead ends, I'm hoping to leverage the awareness of those who already enjoy healthy coffee flavouring syrups that are completely unsweetened.  Even slightly sweetened would be fine, as long as it doesn't consist of recently developed     alternative sweeteners, even of the all-natural variety (I want to avoid accusations of slagging products by mentioning names).  If you are able to divulge what your syrup is, I'd appreciate it.  If you can provide the ingredients and/or nutritional info, either as text, photos, or URLs, so much the better.

From my attempts to inquire about suitable syrups in decades past, I suspect and hope that there are few candidate options that (i) are targeted to coffee; (ii) are completely (or almost completely) unsweetened; and (iii) have their ingredients (and maybe the nutrition) list available online.  If so, then this question is not nearly as open-ended as it may seem at first glance.

The brand MiniSyrup seems to meet your requirements. From their website,

  SUGAR/SWEETENER/CALORIE FREE. Unlike the big bottles of syrup that are crammed with sugar or artificial sweeteners like sucralose and aspartame, MiniSyrup Flavor Shots are the first completely unsweetened flavoring made to flavor your favorite beverages like brewed coffee, hot chocolate, lattes, fountain sodas, tea and more. This gives you complete control over not only the flavor in your beverage, but also your sweetness. [1]

They don't seem to have nutrition information on their website, but myfitnesspal lists the nutrition information for some of their flavors. I'm not sure of the validity, but as you mentioned in a comment you can reach out to MiniSyrup for more information.


Should any coffee be extracted during pre-infusion? I have a Breville Express, 870XL I think, (single broiler, built in grinder). Lately during pre-infusion, a lot of coffee has been coming through before the pressure ramps up, while it's still low and in pre-infusion.

If I put the grind size very fine (a 3 or 4 on the dial) I'll get less during pre-infusion, but even less during the real extraction and also it'll be sour or whatever; you can't taste the flavour of the coffee. This happens both with the single filter and double filter.

I've had the machine for 6 months. Surprisingly the descale light has never come on, so I've never descaled it. I'm trying to keep the grounds even and I use the razor to even out the ground at the end (I blow out excess grounds dug up by the razor).

I'm not sure how to troublshoot this, beyond the different grind settings I tried.

EDIT: I am manually tamping. It looks even when i tamp and I usually tamp as hard as i can without putting my body weight into it, then I use the razor. I try to dose enough, such that after i tamp, I can use the razor to clear off a little from the top, so I know it's even.

Is it possible it's just the beans? This all started when I got new beans from a super highly rated cafe in San Fran, I think. They were already 3 weeks old when i bought them and it's been 2 weeks since then. I just didn't think it would matter for water going through pre-infusion... like how is there even enough water to go through the puck during pre-infusion, I assumed it would barely be enough to wet the puck.

EDIT: Using a fresh decaf bean now from Monogram and I'm having the same issue. It perplexes me that water flows through during pre-infusion and I ALSO still get espresso ranged pressure during the main extraction. Like, if water flows through with no pressure, then shouldn't it flow through faster with lots of pressure? Or instead shouldn't it be impossible to get high pressure, if water can flow through with no pressure? The physics of this whole thing confuses me.

As I said in a comment, I'll lay out a few factors that you need to experiment with.

  If I put the grind size very fine (a 3 or 4 on the dial) I'll get less during pre-infusion, but even less during the real extraction and also it'll be sour or whatever; you can't taste the flavour of the coffee. This happens both with the single filter and double filter.

So this is the first factor: grind size. You can probably still tweak it a bit and you'll want to do so with the smallest step the machine allows. I don't know how many steps your machine has (my Oracle goes from 0 to 45, I think) and it allows a decent adjustment in grind size. It's not as good as a dedicated high-end espresso grinder, but it helps to to tune in the right direction pretty well.

If you're not extracting enough then you're grinding too fine or tamping too hard. So that's why I commented about tamping which is the second factor. Those two are related, if you grind super find but tamp it only very lightly then you'll still get a full extraction. The trick is to find a balance between the two and that can change from one bean to another. So instead of taming harder on the coarser grind, you can also try a finer grind with a gentler tamp.

  Surprisingly the descale light has never come on, so I've never descaled it. I'm trying to keep the grounds even and I use the razor to even out the ground at the end (I blow out excess grounds dug up by the razor).

This is yet another factor. The razor is probably good for reproducibility, assuming it doesn't ruin what remains in the filter. On the other hand, you might benefit from a bit more coffee in the basket, especially when you're using a slightly coarser grind. So this is also a factor to experiment with.

Finally, there's the extraction time. While it's often advised to have about 30 seconds of extraction time, it's certainly not set in stone. Too long and you may get a bitter cup and too short probably won't get enough volume in the cup (or not enough pressure) but it's something to try.

For example, I've had ristrettos taking 40 to 45 seconds on a 1:1 ratio with a fine grind that were nice and sweet. Indeed, had I stopped those shots at 20 to 25 seconds then they would've been sour similar to your description of the very fine grind.

  I would use a finer setting for the grounds, but my pressure after pre-inf is already very high. Like how is water flowing through the portafilter equally fast with and without pressure? I don't understand the physics of it.

In reply to this comment, it depends on how your machine does pre-infusion. For example, the Oracle builds pressure normally but it has a relieve valve that you can set at a percentage of the normal / maximum pressure. The minimum for my setting is 55%, so it certainly builds some pressure during pre-infusion.

As for the flow rate, it probably isn't flowing as much at the lower pressure. You could obviously compare the time and even compare with an empty basket, that'll flow a lot faster (at least on my machine it does).

  I've had the machine for 6 months. Surprisingly the descale light has never come on, so I've never descaled it.

It's probably a good idea to descale regularly anyway. It depends on the hardness of your water, and it's probably not the culprit here, but I'd try to make it a habit to do at regular intervals (monthly, or bimonthly depending on water quality).


Does the hardness of water matter when making coffee? I live in a hard water area and when brewing English Tea I can definitely taste and see the difference when compared to where I'm from, which is a soft water area.

Does the hardness of the water matter when making coffee, too?

For instance, whether or not the taste is more or less intense depending on the hardness of the water. I haven't noticed but I would think it does affect the flavor.

I'd be interested in a scientific/objective view. As of now, I use bottled water in my kettle.

Yes.
That is to say it will definitely affect flavor, but how it affects the flavor is ultimately dependent upon the specific mineral compounds found in your hard water vs. other hard waters and soft water's lack of these compounds.

Here's the key: Some of the compounds in hard water are "sticky," glomming onto certain compounds in coffee when they meet (in your coffeemaker). The more eugenol the water hangs on to, for example, the woodsier the taste of your coffee will be.
Magnesium is particularly sticky, meaning water that's high in magnesium will make coffee with a stronger flavor (and higher levels of caffeine). Hard water can also have high levels of bicarbonate, though, which Hendon found could lead to more bitter flavors coming through.  - A Chemist Has Uncovered A Secret To Brewing Delicious Coffee At Home Business Insider.

So depending on flavor preferences you might prefer your hard water at home but dislike it at work or simply prefer soft water altogether. Traditionally hard water is actually sought after for other beverage processes like beer brewing because of some of the abilities described above.


Coffee consuming amount What's the amount of coffee per day do we need to drink? I study whole day so I feel coffee addicted while studying so can any one answer me?

Prevailing wisdom is that it is generally safe to drink up to 4 cups of coffee per day. Caffeine is the world's most widely consumed psychoactive drug (stimulant) and typical consumption is alleged to have a number of positive health benefits.

The U.S. 2015 Dietary Guidelines Advisory Committee recommended a similar limit. Lower limits are recommended for pregnant women, adolescents & children.

Lethal caffeine overdoses are rare and estimates of a lethal amount of caffeine in a healthy adult range from 10,000 - 20,000 mg.


My home machine is broke. The single basket works but the double basket doesn't. Can baskets be broken/worn out? My sunbeam em5600 coffee machine isn't working. It's worked unreliably but now it seems to be consistently not working. Plenty of water comes from the showerhead when there's no group handle in. I am able to get steam  from the steamer but it runs out of steam quickly. I can't get any hot water stream from the steam wand.

When I put a single basket in the group handle it works. When I put fine or coarse or nothing in the double basket nothing comes out anymore. I have occasionally seen a drop of water coming out over the top when the group handle is in but nothing more so I don't think it's the rubber ring. When I take the group handle out after a failed attempt there is a squeak noise so there definitely water built up under some sort of pressure. I soaked the baskets in vinegar for at least 12 hours last night, didn't help. I cleaned the machine every few months which is far more often than what the manual recommends.

For as long as I've had the machine which I got used I find the large water reserve can't fall below half for the machine to work.

I do tend to aim for a very fine espresso grind, but it works in the single basket. My grounds have never formed the hard biscuit that you get when using professional machines.

Is there a simple fix here like a new ring or basket or is it the water pump? If so how hard would it be to replace on my own?

It's basically impossible for us to know what exactly causes the problem, but it does seem to me as if the basket is clogged with something. Probably built up residues of the coffee and fiber that's stuck in the small holes. It could of course be the pump, but then water would definitely flow out if you run it empty and the single basket should be affected as well.

If it's clogged filter you can try soaking it in hot water with an espresso machine cleaning detergent over night. But since you already soaked it in vinegar I don't think that would be fruitful.

You can also, carefully, put the porta filter over a gas stove to burn the residue. Hold it over the flame for a bit until it gets hot enough to burn it, then tap it against your kitchen table or some other heat resistant surface. That should do the trick. Afterwards you can clean it again normally and it should work again.

Lastly you can of course push through the holes with a very thin needle, but that is quite tedious work and would take a long time.


How do I effectively clean a metal Chemex filter? I've been using a metal cone filter for a couple months: Able Brewing Kone Coffee Filter

It has worked fantastically, but gradually clogged up over time. I've washed it with warm water and dish soap multiple times to no avail. Anyone have cleaning tips? Or do I just have to buy a new filter?

This problem seems quite normal. Over time, the little holes are filled up with small coffee grounds and stuck there by the help of gluing force of grease. This grease is extracted during brewing process.
So, how could we get rid of these remains?
Pretty easy. As they are organic compounds, you should dissolve them. As they include grease, dissolve the oil that includes particles.
Best options are:

Heat (self cleaning oven or BBQ)
Acetic acid, thus vinegar
Citric acid, thus lemon juice

Heat is the most effective option as it burns out the organic compounds without leaving any residue. Place the filter in the oven or BBQ while doing a cleaning cycle. You’d be amazed  at the results.
Check the comparison: Before cleaning After cleaning
As for the to other options, These acids are food, so they are safe to use. You may leave the filter in these for a while. Apart from that, you may try alcohol, but check whether it damages the filter.
Last option may be bleach. It dissolves any organic compound quite easily as it is corrosive. However, it is not safe. You must rinse it thoroughly.


Is it possible to grow plants in used coffee ground so that they get coffee flavor? Is it possible to grow any kind of fruit or vegetable in coffee ground (instead of normal soil) so that they get coffee flavor? If yes, which fruit or vegetable works best and what do I have to consider when doing this?

Adding coffee grounds to a planting medium (e.g. soil) adds fatty acids, essential oils and nutrients that enrich soil which can help the growth of the plant and it may also affect the colour. One thing to be careful of is that some coffee grounds increase the acidity of the soil. However, I can't find anything indicating that it will affect the flavour of the plant. So, by all means, grow your plants in coffee grounds, but don't expect any difference in flavour.


Does coffee really need to be stored in an air-tight container? I am getting conflicting information online about whether or not coffee needs to be stored in an air-tight container. There seem to be two camps:

Container must be air-tight
Container must have CO2 vent

Even coffee canister manufacturers seem to be at odds with one another. Take the following two products for example, both of which I own. The first is air-tight with a strong vacuum seal whereas the second has an opening in the lid that takes the same type of CO2 filter you see in commercial coffee bags (in fact, I will tear them out of the bags and use them with this canister as they're usually the same type as the ones that initially ship along with it).

So what is the final answer as to the proper way to store coffee, specifically whole beans in this case? What are the implications of CO2 build-up in the canister if you open the canister several times per day? Is the CO2 filter on a home coffee canister just a gimmick that only serves a purpose on coffee bags that sit on a shelf sealed for days or weeks on end?

How to store coffee beans is a much opiniated area. Degassing CO2 from coffee beans is most important right after the coffee has been roasted, since it would release a lot there and then gradually release less and less over days and weeks.
If then beans can't release the CO2, then there will be a buildup and since CO2 tastes sour, then it will affect the coffees taste.

Coffee should in general not be stored for too long after it's been roasted, since that will also negatively affect the taste. Storing it dark, dry and airtight will potentially keep it fresh a bit longer, but the best is in my opinion 1 week after roast and before 4 weeks after roast.


Pressurized vs non pressurized filter baskets I own a DeLonghi Dedica coffee machine for a year now and recently invested in a good burr grinder (Sage Dose Control Pro). I like drinking long coffees with milk and I’m satisfied with the coffee the DeLonghi machine produces.
The machine comes with pressurized filter baskets, and after doing some research online I found that non pressurized filter baskets can actually create even better coffee. So I decided to buy a naked portafilter with a non pressurized filter basket on Aliexpress.
However, I am still struggling to get something good out of the non pressurized one. Often it is so strong and bitter that I can’t even finish it and I can’t wrap my head around why this is happening.
How is it possible, given a same dose of ground coffee and the same grind setting, that with a pressurized filter basket I can create a coffee that’s actually pretty nice, and it doesn’t even matter how much water runs through the coffee grounds, if my tamp was level, etc., but with the non pressurized basket I can’t get anything drinkable?

You will need to grind a lot finer with the non-pressurised baskets.
With a pressurised filter basket, the resistance is mostly produced by the one tiny hole in the filter basket. For non-pressurised ones, the coffee needs to provide the resistance.
If the grounds fail to provide enough resistance, the water will run through the coffee really fast, probably creating a bunch of channels which you can usually see as little holes in the coffee bed after the extraction. The problem with the channels is that most of the water goes through the channels (over extracting the coffee there) instead of evenly extracting all available grounds.


What do I need to start cold-brewing? After reading Cory Doctorow's Homeland, I started wondering about making my own coldbrew; it sounds delicious :)

What do I need to start my own cold-brew?

There are two ways to start with: plunging and dripping.

Plunging is to mix water with ground coffee, and let the mix sleep slowly.
Dripping is the same as classical hot-water dripping, except the speed is much slower.

The slowly / "much slower" part means about 8-12 hours, depending on the quantity of ground. For example, I use 400mL/14oz and 40g/1.5oz of ground on an 8 hour drip.

The beans should be quite finely ground, as cold water does not penetrate the ground as well as hot water.

@henryJ exposed plunging in detail. As for dripping, it is possible to use a standard filter stand and paper filter.

The hard part is to drip water slowly. There are cheap devices on the market. An alternative is to get one of those flasks used in chemistry class (a new one, never try with a used one---chemistry is scary). The cheapest way is probably to get an empty plastic bottle, put the cap on, use a needle to make a tiny hole in the cap, fix the bottle upside down above the ground to start dripping. The goal is for the water to pour drop by drop, at a rate of about 1 drop every couple seconds.


Gifting coffee beans, how to put effort into them and make their taste interesting I am an amateur when it comes to coffee. My dad drinks a lot of coffee and enjoys preparing his coffee.
I have bought him a coffee grinder for his birthday (he usually just buys ground coffee). I have also bought green coffee beans to roast. Is there anything more I can do besides roasting the coffee beans ? I would like to show I put effort into them and give them a unique taste. I have plenty time and coffee for trial and error.

Is there anything more I can do besides roasting the coffee beans?

I'm not sure you can even roast them - at least probably not properly. Roasting coffee requires precise temperature control which is incredibly hard to achieve with a popcorn machine, an oven or a pan.

I would like to show I put effort into them and give them a unique taste.

After picking the coffee cherry you cannot really add any quality or characteristics to the bean. The whole process can be seen as a series of windows - if everything is done well, you can see the coffee and its origin characteristics. If something is not done well, the window gets stained and the view on the coffee gets muddy. The main thing you add with roasting is sweetness, notes that go into the chocolatey and nutty area and bitter/burnt aromas.

I have plenty time and coffee for trial and error.

If you really do want to roast them yourself despite not having the ideal tools for it there are several things to keep in mind:

Make sure all of the beans are roasted evenly. This means keeping them moving a lot and not letting some beans be in contact with the heat source for too long.
Do not roast them beyond the second crack if your father does not like overly bitter coffee.
You're dealing with temperatures of above 200°C, take appropriate precautions.
Remove any defects like chipped beans or quakers afterwards so they don't negatively impact the taste.


Does ground coffee lose caffeine like it loses aroma? What I know is that, for the best taste, one should grind the coffee right before brewing it. Storing ground coffee makes it lose part of its taste, even if there are ways to counteract that effect. However, assume I ground up some coffee and left it in an open conatiner for several weeks. Would the coffee lose any caffeine, i.e. would I feel the effects of the coffee less than if I had brewed it directly after grinding?

If yes, what mechanisms are responsible for this and how does the caffeine leave the coffee?

Caffeine has a very very low vapor pressure 9.0X10-7 mm Hg at 25 deg C.  Source

Almost none would evaporate.