What purpose have those grooves inside the dripper? I'm using the V60 dripper from Hario and was curious about the grooves inside the dripper. I think that they are present to slow down the water running through the filter and let the water pass as much as coffee powder as possible, but I'm not really sure. Is this really the intention of this grooves?

These grooves are for improving the flow of coffee through the filter. The grooves create space between the filter and the cone to permit little channels for the coffee to flow into the vessel after passing through the filter paper. I think the ridges also help "wick" the coffee away from the filter paper, helping the filter paper drain better.

If the ridges are absent (as in Chemex cones, for example) the brewed coffee sometimes wells up between the filter paper and the cone. See also this question and my answer that compares the two styles of cones.

As for the shape and location of the grooves, some are spiral-shaped, others are straight, staggered, etc. I don't notice any advantage of any style as long as they're present, and I suspect the shape and location is purely aesthetic or marketing, not significantly different in any functional way.

EDIT: this article from Serious Eats suggests that the grooves additionally help "keep water distributed evenly among the bed of coffee grounds." Presumably this is related to the drainage I mention above, but was a more-legitimate source than my theories above, so I wanted to include.


Pouring espresso into hot water versus hot water into espresso struggling to find an answer to this (if there is one), perhaps because nature of the question doesn't work so well with search engines.

Essentially, I've noticed (and so have others I've spoken to about this), that if I make espresso in a moka and want an Americano style coffee (i.e. hot water mixed with espresso -- please don't crucify me if this isn't the correct definition of Americano) then it affects the taste significantly if I make it in these two ways:

Boil water in kettle, pour water into mug, pour moka espresso into hot water in mug -- the two mix -- then drink.

v

Boil water in kettle, pour moka espresso into mug, add hot water into espresso in mug -- the two mix -- then drink.

I've noticed the first method produces a nice, smooth Americano that's nice to drink... whereas the second method (coffee in first, add water) produces a relatively less pleasant, sometimes unpleasant, bitter (perhaps?) and very inferior drink.

How is this possible? My only guess is perhaps it's a chemistry thing to do with some kind of oil in the coffee? Or it just mixes better the other way? I have no idea but I swear this difference is real and so do some of my friends, but none of us know why.

Thanks...

I would suspect that a few centigrades make all the difference here. With coffee, too high temperatures will negatively affect your flavor. Rule of thumb: Hot is good, boiling isn’t.

If you put the water in your mug first, you’ll lose just a bit of temperature as the water warms the mug and/or stands for a bit until you add the coffee.

If you reverse the order, you are effectively scalding (some of) the coffee with the boiling water, losing volatile aromatic compounds and degrading others.


How is Nescafé made? How is Nescafé (or any other instant coffee) made? Do they brew coffee and then dehydrate it (like they do it with instant soups)? Or is it done another way? What ingredients do they use to produce it?

A quick Google search led me to this.
It's a very detailed site that explains everything you need.


Why does coffee lose caffeine as it is roasted? I have heard that coffee actually loses caffeine as you roast it, which means darker blends have less caffeine. Why is this?

This is a very common misconception.  Coffee does not lose caffeine as it is roasted.  It is often misunderstood that darker roasts have less caffeine. Caffeine's melting point is 455F which is well above what most beans reach during the roasting process. Essentially, caffeine content changes because the mass/density of the beans change (they lose water and undergo changes in the roasting process). If you measure your coffee by volume, dense greener beans will have more caffeine. If you measure by weight, darker roasted beans will have more caffeine.  The total amount of caffeine in a batch of beans changes very little, if any.


Do I need to use a tamp if using a Moka pot stove top espresso maker? Can I just add the coffee powder to the basket and let the the water vapour do the work or should I make use of a tamp same as with a professional Espresso machine?

You should not tamp the coffee in a Moka. These pots don't like excessive pressure, which tamping would produce due to increased density. This is also why the water should not cover the steam valve. In the worst case they can literally explode!


What do the terms extraction and strength mean? A number of questions use the terms extraction and strength in a broad sense like "how much stuff comes out of the coffee beans."

But "technically" speaking: What do the terms extraction and strength really mean for coffee?

Some selected questions that discuss (but don't define as such) strength and extraction:

Coffee package strength markings are often just relative to others within a brand;
Effect of stirring on extraction;
Extracting caffeine and other compounds;
Hot versus cold extraction;
This one and this one about espresso extraction.

Though I don't generally like to cite Wikipedia as my primary reference, it does in this case have a pretty good overview of terms related to coffee extraction, re-summarized here:

Extraction:
The amount of the original mass of the grounds that ends up in the brewed coffee. Though it certainly depends on the preparation method ("method of extraction", e.g., drip, moka, espresso, cold-brew, ...), the recommended extraction amount is about 20% (i.e., about 20% of the mass of the beans/grounds ends up in the brewed coffee).

Less than ~15%-18% extraction is considered "under-extracted" and can be sour. That is, under-extraction is not just a matter of inefficiency: the result can be sour and unbalanced due to the fact that acids are extracted quickly. On the other hand, more than ~22%-25% extraction is considered "over-extracted" and can be bitter, because the bitter compounds are extracted later in the brewing process.

These figures were generated by groups with lofty-sounding names like the Specialty Coffee Association of America, the Coffee Brewing Institute, and the Italian Espresso National Institute. Also known as "solubles yield." See also this article on espresso extraction.

Strength:
The concentration of the extracted compounds in the water. Basically, how much coffee is in the water per unit (volume or mass).

As noted in the question, there are also colloquial or vernacular uses of these terms (e.g., "strength" as relative flavour profile; "extraction" as the process of brewing, etc.) but the above seem to be the accepted tangible definitions of the terms.


What does the 'strength' mean (in numbers)? The coffee package I've bought has 'strength rating'. It's 3 out of 5.

I wonder what that 'strength' means? How it is measured? Does it relate to the caffeine amount?

The coffee package is from Germany, and from what I've seen, all coffee sorts have this rating, so it's a kind of standard.

Coming from Germany myself I have seen this rating only on a single brand of coffee. There is no standard for this (even though us Germans seem to like standardizations), but basically strength of the coffee is about the inherent bitterness and caffeine content you get out of it.

The stonger a coffee the more caffeine and also the more bitterness you will usually get.


How many plants are needed to brew a cup of coffee? I am curious. How many coffee plants do I need to harvest for beans in order to brew myself one cup of coffee (7g of ground, processed beans).

If it is less than one, then how many cups of coffee can I theoretically brew from one plant?

It all boils down to three questions:
1) Yield = How much did you get from the grounds?
2) Strength = How much ended up in the cup?
3) Ratio = What did you get there?

Yield: Yield pertains to how much soluble you took from the coffee grounds. Ground coffee has something between 27-30% of its mass being soluble, that is, stuff you can dissolve in water. If you kept boiling and boiling coffee grounds in water, eventually you’d get everything that the grounds have to give. Above 22-24%, however, and you’ve essentially reached too far or squeezed too hard, because unpleasant flavors will emerge. Below 18%, and you’re not getting enough out of the coffee, at worst, leaving the coffee with underdeveloped flavors or simply wasting coffee. So it sort of answers the question, “How much did you get from the grounds?”

Strength: Pertains to how much of the final brew is coffee, and how much is water. SCAA Golden Cup says 1.15-1.35% brew strength is a desirable zone to the most number of people, though we espresso-lovers tend to like a bit more… something like 1.3-1.5% brew strength. Over 1.5, up to 2.0% or more, and you’re in the “heavy, thick” coffee zone. Simply put,“How much ended up in the cup?”

Ratio: Simply, grams per liter. It provides one of the major answers to the question that Yield and Strength might ask, that is, “How did you get there?” Perhaps the most easy-to-remember ratio is 60g/L, or 60 grams of coffee for every one liter of water. The fact that you can make a balanced, pleasing, delicious cup of coffee at 60 g/L should give any barista pause when they’re finding that they’re using 80 grams or more per liter when they’re making coffee. Is it “wrong” to make coffee at 90 g/L? No… but is the additional 50% of coffee yielding an additional 50% of coffee quality, compared to the barista down the street making superb coffee at 60 g/L?

For the assistance of common men like me,

Then, to clarify the actual number, if Arabica then 1 - 1.5 pounds per cycle and if Robusta 2 - 2.75 pounds. And then you can calculate the rest. ;)

Sourced from http://portafilter.net.


Adding vanilla extract to coffee? To sweeten coffee, instead of using sugar, I am putting in a few drops of vanilla extract. What other substitutes can I add to coffee for a different taste?

Can I add almond extract?
Can I use vanilla essence instead of vanilla extract?
Can you put honey in coffee?

Do what comes up in your mind. I like to add cinnamon and Jamaican pepper. They don't change the flavor but brings a lot of aroma.


What are my options for approximating espresso at work? Lately I have developed a taste for espresso during the day, when I'm at work. There are several problems:

There is no espresso machine at work.
There is no stove at work, so a stovetop moka pot is not an option.
There's no time to leave the office to get a coffee.
There is no chance of putting an espresso machine in the office (not even Nespresso): I would be the only user.

I've thought of two solutions, neither of which is very appealing:

40-60 mL of really strong instant coffee: ugh.
Aeropress coffee: a lot of setup and fiddling for something that doesn't really scratch the itch.

I do have an Aeropress, so that'll be the solution if necessary, but does anyone have a better idea?

I don't want to provide any specific product links here since they may change in the future and I also don't want to advertise specific stores.

However there are some options I can think of. There are electric Moka pots that have the stove already built into them. Bialetti is the go to brand for Moka pots. I'm certain that they will fit in your office, even on your desk if need be. Alternatively you can get a small electric stove for the Moka pot you already have. It will also fit on your desk.

Another option would be portable espresso makers. Handpresso Wild Hybrid and Wacaco are the only ones I know of. I've heard good things about the Handpresso, but can't attest to them since I haven't tried one yet. They work with pressure, which the Moka pots don't do, so they should come closer to Espresso from a machine.

However I personally would stick with the AeroPress. In my opinion it makes by far better, more complex coffee than the other options.There are also some tweaks, like using two filter papers, using a metal filter, very fine grind size, tamping the coffee, high coffee to water ratio and tweaks/constructions to apply more pressure, that make a more espresso like drink. Note however that the AeroPress is not built to withstand several bars of pressure and constructions like the one in the video are neither practical, nor safe. The other tweaks mentioned however can safely increase pressure to a point where you get pretty neat, espresso like results.


homemade cleaner for basic drip coffee maker Is it possible to create a cleaning agent to use on a basic drip coffee maker using household items? If so, what ingredients are needed and in what ratios?

I am mostly concerned with cleaning the insides that I believe are made from plastic. The carafe I can clean separately. I know that there are products on the market, but I am interested in homemade solutions.

Ordinary white vinegar works just fine, but the smell bothers some people. If so, use citric acid. You can either pick some up at your local grocer, or order it by the pound. I use about a tablespoon to a quart for descaling. It's gentle, has little or no odor (you may smell gasses released by the dissolved scale however), and safe unless you get it in your eyes.


Does this look like a decent coffee grinder? I found it at a yard sale. It's cheap. Does it look worth purchasing?
I usually brew my coffee in a percolator (or is it called a mocha brewer?), so I'd like to use it for that.

It looks like a burr grinder, as opposed to a blade grinder. Burr grinders give a more consistent grind size, which is why they're preferred over blade grinders.

My guess is it's made of steel, but it does look tarnished. You might take it apart and polish it to create a smoother grinding surface.

The wood on the inside might be difficult to clean of coffee oils and impart an odor to your freshly ground coffee.

I can't tell if the mechanism has a means of changing the grind size. If not, it may in fact be an old spice mill. Otherwise, it won't allow you much variety when grinding your coffee.

If it's given a little TLC I think it would make a nice vintage manual grinder. Compared to blade grinders, even this older grinder ought to do a better job than they ever could. However, if you can't change the grind size than you'll be limited in the type and quality of the coffee you can brew using it.


What's the recommended method for heating cold brew? I have recently started enjoying cold brew (over ice) in the afternoons. In the morning I still like my coffee hot. Is there a preferred or recommended method for heating? What factors should I take into account? I have tried adding hot water, but it makes the coffee too weak before I am able to get the temperature up where I want. Microwaving seems to negatively affect the taste.

The best result I got was warming up in a bain-marie. No science here---just my trials... I believe for now that bain-marie preserves more flavours and "respects" the aromas.

Heating cold-brew coffee was surprising to me the first time. Such unexplored flavours with the exact same beans I use for drip, etc. I hope you'll enjoy, and explore for more questions here!


How does freezing affect vacuum packed coffee beans? I recently vacuum packed 1 kg of coffee beans that were about to expire into 100 g portions.

I would like to know how they will be affected by the freezing and how long they will last in the freezer.

Freezing will not affect the coffee beans chemically. Thawing may affect them though.

When you thaw the beans, small amounts of water (that were frozen as small amounts of air humidity) will melt and it may collect together and cause some very small extractions in the bean. This is probably quite minimal due to the fact that you have vacuum packed the beans though. This is generally undesirable but it is up to you whether or not you want to do this.

If you do indeed freeze them, make sure that you let them thaw completely before opening the package. Do not open the package until they are back to room temperature. This is so that the humidity can stabilize inside. If you open the package earlier, moisture from the air may condense onto the beans, causing a small amount of extraction.

In terms of how long they will last in the freezer? I am unsure of this as I have never frozen my beans as it is not recommended.


How can I determine the origins of coffee beans in a blend? Is there a method exist to understand the type of the beans in a blend?

More specifically, I will be glad if I can find a quantitative way

to determine the origins of the beans in a blend
or if this is not possible, to determine whether the beans are from Africa or America (or Robusta)
if possible, with relatively easy gadgets that I can find at every house. No gas chromatography, FT-IR, etc.

Apart from that, any other suggestions?

The short answer is no.  Short of genetic testing, it is near impossible to determine the origin of beans.

You may be able to make an educated guess at the whether or not Robusta beans are in the blend based the shapes of the beans and caffeine content.  But that would require a trained eye as as there is a great amount of variation in beans and it might be possible to mix up robusta, natural peaberrys, etc.  Robusta will raise the caffeine content, but depending on the blended amount, it may be hard to detect.


What variables in brewing have the biggest effect on taste? I've been brewing my coffee with an AeroPress for a couple of years now and I've become aware of the huge number of variables available to me in making my morning Java.  Assuming the same bean and roast level, I see

amount of ground coffee,
grind coarsness,
temperature of the water,
steep time, and
using the AeroPress right side up or upside down,

as the variables I can play with to vary the taste.  Some of these variables may offset each other as well.  For example would steeping coarser ground coffee result in the same taste as less time steeping a finer grind?  Or how about coarser ground coffee in hotter water v. finer ground at lower temperature?

I'm searching for the key variables in my control to play with to maximize the effect on taste.

A few other factors to consider:

Freshly ground beans.
How you store your coffee beans. You basically want to keep them reasonably cool and away from oxygen, sunlight, moisture and variations in temperature (which is why you don't keep them in the freezer except for long term storage). Generally in the pantry in an opaque, air-tight container. I one-way valve is recommended as recently roasted beans will emit CO2. I bought a stack of 250g resealable foil bags with the one-way valve from a local roaster and would use each bag a few times. These days I use AirScape canisters.
The water you use. If you wouldn't enjoy drinking your tap water, don't use it to brew coffee. Use the same water you use for drinking water.
The amount of water you put in the Aeropress vs. the amount of water and/or milk you add afterwards (if any).
How vigorously you stir with the paddle. Generally you want to stir just enough to ensure all the grounds are thoroughly wetted, and that there are no air pockets. Stirring too much can over-extract which will increase the bitterness.
When pressing into the cup, do you only press until you hear the air hissing through, or do you keep going and compress the puck, squeezing out every bit of water you can?[1] The latter can over-extract and increase bitterness.
Using paper filters vs. a metal disc filter. Also, some people believe pre-rinsing a paper filter makes a difference.

Obviously there are a lot of variables, and people can become amazingly pedantic. Fun if you don't mind a bit of experimentation.

With regards to water temperature, the general wisdom is that you want the slurry of coffee and water to brew at around 95°C, which is just a bit under boiling for optimal extraction. This video gives some pretty good advice on this. Pre-heating the Aeropress would probably make the biggest difference here[2]. I usually just wait until the water in the kettle stops bubbling before pouring. Apparently it is possible to burn the grounds if you hit them with water that is boiling.

The other bugbear I have is with retention in coffee grinders. Retention is when grounds are left up in the works of the grinder, and often the grounds can come out very staticy and cling to everything and make a mess. This grosses me out as it means old grounds from previous grinding will be dropped in with the fresh grind. Weighing the beans before and after can show a variation of half a gram or more. Urk.[3] However I've found that sprinkling a couple of drops of water on the beans before grinding almost completely eliminates retention for me.[4]

[1] There's a term for over-squeezing the grounds that escapes me at the moment.

[2] Having lived a lot of my life in drought areas, using and then discarding the water to pre-heat my Aeropress or French press is something I find surprisingly hard to do.

[3] I did mention people can become amazingly pedantic, didn't I?

[4] Known as the Ross Droplet Technique


Is it easier to froth full-fat milk? Is it better to use whole (full-fat) or semi/skimmed milk for a cappuccino, or does it make no difference (other than the taste)?

Will one type of milk be easier to froth?

The short answer is yes. The absence of the milk fats means that the foam will not "coagulate" as easily.

The proteins chains in milk are polar: one end of the chain is
hydrophilic (attracted to water), and the other is hydrophobic
(repelled by water). Because milk is mostly made up of water, as soon
as those proteins unfold, exposing their ends, the hydrophobic ends
immediately try to get as far away from that water as possible. If you
were to look at a single tiny bubble in a cup of foamed milk, you'd
see that the hydrophobic ends of the milk proteins are all pointed
inwards, towards the water-free interior of the bubble, while the
hydrophilic ends stay put in the aqueous environment the bubbles are
suspended in.
This structure helps keep the air bubbles intact for a long time after the steaming > process, all the way into your cup (and into your happy, soon-to-be caffeinated mouth).

For a wonderful article on the topic see:
http://drinks.seriouseats.com/2013/12/milk-foam-what-is-microfoam-why-does-milk-foam-what-is-a-cappuccino-coffee.html


What's the theory behind using thin spouted kettles when making drip/pour over coffee I own a drip coffee pot:

and one of the other things you can buy is a thin spouted kettle which is used for pouring water one to the grounds.

What is the theory behind this?

Does the rate of water delivery/flow just agitate the suspension of coffee/water in a way that is better?

I also see such items being used in coffee shops too so would really like an expert's summation on this.

By having a thin spout, you can more finely control the flow rate and where the water lands.    When making pour-over coffee, you want to control the water level in the cone to control the brew time and evenly extract coffee.  Also, water needs to be poured carefully onto the middle of the cone so that the water doesn't run down the side of the cone without touching the coffee grounds.


Pouring technique for drip/pour over coffee I would like to know how to make decent coffee using a drip (pour over) coffee.

The kit I bought was from Japan and I observe in espresso shops they tend to use a thin spout (or gooseneck) water kettle to control the rate of delivery of water.

What else is important here aside from the fineness of the ground coffee?

Are there a recommended set of steps?

Should I pour from the middle outwards or edge towards the centre?

Should I 'wet' the coffee first?

Is there a recommended pouring time to perform all of this?

From this site:

  Start with a grind size around that of coarse sugar. (Think Sugar in the Raw.)

  How much: Most pourover drippers work best when they're between one
  half to two-thirds full of coffee grounds. Any less than that, and
  there won't be enough coffee to restrict the flow. Any more, and your
  dripper may overflow. You'll also want to make sure you're dripping
  into a large enough vessel. If you're the more precise-measurement
  type, a good coffee-to-water ratio is between 60-70 grams of coffee
  per liter of water (a mass ratio between 1:16 and 1:14.)

  Get your clean (filtered if you need it) brew water ready. You'll be using water that's about 30 seconds off boil if you're pouring
  straight out of your boiling kettle, or immediately off boil if you're
  pouring into a second pouring kettle. I like about 207°F for medium to
  light roasts, and about 10° lower for dark roasts.
  Start your clock and add enough water to soak all of the coffee (a little premature dripping is okay). Wait for the coffee bed to stop
  the initial swelling (about 30 seconds) before adding more water.
  Continue your brew. Try to pour quickly, gently, and evenly across the surface of the coffee, pausing between pours to pace your brew to
  your target brew time (see below). The distance that your brew water
  drops can affect brew temperatures, as well as increase or decrease
  the amount of agitation that the falling water creates wherever it
  falls in the coffee bed. In general, the lower you pour from, the
  better, if for no other reason than it's the easiest to create and
  maintain consistency.

  When you stop adding water, your dripper will continue to drip for
  between 20 and 60 seconds.

  Your target total brew time is about 2.5 to 3 minutes for dark roasted
  coffee, and 3 to 4 minutes for medium to light roasted coffees. This
  includes the dripping time after you stop adding water.


What was the cause for the current overwhelming popularity in the brighter, more acidic coffees? Almost every coffee shop I go to serves up quite acidic and bright coffees. It seems that this is where modern coffee is and is not necessarily a bizarre phenomenon in itself but in particular the world of espresso it has veered quite far away from the traditional Italian style.

In fact it seems we've veered so far towards acidity and people have actually called the Italian style of espresso as 'over-roasted' which I believe to be untrue. I do enjoy a somewhat more acidic coffee when I am searching for a fruitier cup but I do not understand the current stigma against even the slightest darker roast.

So what caused this tip in the scales that prompted the surge in popularity in brighter and more acidic coffees and seeing even the slightest darker roast as being over-roasted?

I think there are a number of factors influencing the current situation.

The rise of micro/small and home roasters.  This allows people access to fresher coffee.  The acidic and bright notes in coffees tend to fade quicker than roast notes.  Meaning these bright notes are more readily available to the consumer.
Changes in coffee processing.  Different process methods favor different flavor profiles.  Dry Process (the oldest) favors less bright and more bodied flavors.  Newer processing methods enhance bright flavor profiles.
The rise and market dominance of large chain roasters.  These companies tend to roast dark because it is easier to hit a consistent flavor profile which lasts longer (important for shipping), but it sacrifices the origin flavors which are varied greatly and available.  They have given dark roasts a more McDonald's character among consumers (consistent, but not high quality).

This is not to say that dark roasts are bad.  But they have partially been given a bad rep by large chains who are using them to maximize profit, and not flavor.  Home and microroasters now also have unprecedented access to a HUGE variety of beans that years back would have been out of reach.  This means that companies can cheaply distribute very high quality beans with extraordinary flavor profiles when roasted at a lighter level.


Why is coffee sometimes nitrated but never carbonated? I've seen a lot of cold "draft" coffee appearing that is infused or pressurized with nitrogen gas (as with Guinness beer).  The added nitrogen leads to a "smooth, creamy" mouthfeel.  (Although it seems to dissipate very quickly – over a matter of minutes.)
I've never seen carbonated draft or bottled coffee – i.e., coffee infused or pressurized with carbon dioxide.  Dissolved carbon dioxide occurs naturally in sparkling spring water and fermentation, and is the gas added to most "sparkling" beverages.  Is there a reason cold "sparkling coffee" is not an item?

Carbon dioxide when mixed with water renders the water slightly acidic and changes the flavor of the beverage. It may also react with molecules in the coffee. Nitrogen is inert and will neither lower the pH of the coffee or the topping nor react with the coffee's compounds in other ways.


Does the coarseness of the ground coffee affect taste I've just taken the plunge, and purchased an Espresso machine. (Sage Express) I'm now officially an amateur barrista in the making. :)

From what I can gather, there are two important parameters in making the best possible coffee. (Well, three actually. But I'm keeping your personal choice of coffee beans out of the equation here.)

First is temperature of the water. The machine takes care of that for me. Check.

The next is how long it takes for the water to run through the grounded beans. This should be around 25 seconds. Your personal taste may make it a bit higher or lower.

Now I've got the grinding of the beans, and how coarse or fine that should be. Does this affect the taste directly, or is that just one parameter combined with how hard the beans are pressed, that goes into how long the water takes to run through? Or does this by itself have a more direct effect on the taste?

I can always try to experiment a bit, but would like to get a bit of insight beyond that. Thank you. :)

Required reading for any aspiring home barista: https://www.home-barista.com/tips/espresso-101-how-to-adjust-dose-and-grind-setting-by-taste-t16968.html

Basically, coarseness of the grind influences the balance of bright and bitter flavors: coarser reduces bitter flavours, finer reduces acidic flavours. But it all interacts with the flow rate; see the diagrams in the linked article.

Tamping pressure itself is not really a factor, you should keep this constant and only modify grind and dose.


What factors determine coffee bean size? I bought a bag of Guatemala/Colombia/Ethiopia blend after having single origin Peru beans (all Arabica), and was struck by the difference in bean size: Peruvian beans were almost twice larger than the beans in the blend.

Now I'm wondering whether the difference is conditioned by some environmental factors, or regional differences of the coffee plant, or the timing of harvesting. Of course, it can also be that any coffee plant anywhere produces beans of (significantly) different size, and then they are sorted into size-consistent batches (as per this guide, for instance).

The single biggest factor in the size of a coffee bean is the botanical variety of the plant. There is no amount of nutrition or growing conditions that can overcome the effect of genetics.

In this picture from our garden at Coffea Diversa you can see two examples at the extreme.

On one hand you have mokka, this variety has the smallest bean of all
coffee varieties.
On the other hand you have Maragogype, this variety has the largest
bean of all coffee varieties.

There is no amount of fertilizer that you can give to a mokka grain to make it even come close to the size of a ripe Maragogype bean (and viceversa).

The difference in sizes between your blend and peruvian coffees are probably due to the botanical varieties of the beans.


How Can I Program A Robot to make coffee For me when I wake up? Would a Raspberry Pi work for this?
Or maybe one of those android robots?

I don't wake up at a certain time everyday its totally random, so I cant use a Timer I need a sensor that will sense if i'm awake.
Please email me if you think the same as me.

Sure you can. Get, for example, a PR2 robot and program it accordingly. You can also use simpler robots, but in all cases, you will either end up with a ridiculous amount of cost, or with a very unreliable performance. Not mentioning the hours of programming time you will have to spend on the project.

You may be better off buying a coffee maker that you can control remotely, e.g., via Wifi. Use the app to start the coffee making process once you are awake, or program your phone to detect that and start it for you. In industrial settings, robots are almost never the answer for tasks you can do without (e.g., button pressing). This is not so much different.

(I am not affiliated with any of the producers of the products linked to in this post.)


What actually happens with the ground coffee that lost its flavour? Ground coffee looses quickly its flavour. It's especially painful for singles living in rented apartment (no coffee machine) and having only big packages in nearby groceries...

But what actually happens to that coffee? What is lost, other then flavour? How the taste is affected? Does the caffeine amount also changes? Do some chemical processes happen, that can make such an old coffee unhealthy?

As far as I know the aroma is gone first, the oils begin to dry out and the taste goes down as well. I don't know how long it takes the caffeine to go away. I have drunk coffee over a year old and there still was caffeine. (I go camping and there was a bag left over from the previous year.)

On a different note - as a lifelong NYer I don't see how living in a small space precludes having a grinder. Even - gasp - a cheap krup kitchen grinder is better than buying bags of store ground coffee. (IMHO) Although I would buy a hand grinder instead.


Does hydration level change the effect of caffeine? Apologies if this question does not belong here, it may be suit for the chemistry site, but it pertains to the consumption of coffee directly -> so here it is.

Does your prior level of hydration have any affect at all on how much of a "buzz" the caffeine from coffee gives you? I spoke to someone who thinks it's the case that having drunk a glass of water before coffee sustains the effect versus it being the first liquid introduced into your system and the rationale behind that was since your body is not in need of any liquid the effect of the caffeine is somehow prolonged.

The other side is that if there's nothing in your system and only the coffee, is it the case that its effect would be stronger since it would not be diluted with other things (e.g., water) in your system?

Has anyone experimented with this?
Is there any difference at all?
What are some resources for explaining the biochemistry behind this?

Definitely. This is why you get caffeine jitters when you drink coffee on an empty stomach. Caffeine is a diuretic so it makes you more dehydrated. It is recommended to drink water before drinking caffeine, because caffeine also increases stomach acid and can cause stomach pain.


Using Nescafe Gold on Espresso Maker I'm very new to the land of brewing your own coffee, I just thought of making my own coffee, until now, I have only drank tea and tried the ready made coffee sachets that were available in the market.

I have this Espresso Maker

and I bought this Coffee blend,

My question would be if I can use this blend with my maker, or do I need something different. and If I need something different, which product would be recommended?

Absolutely not!

The Nescafé is not coffee in the sense of coffee beans, ground, ready for brewing. It’s instant coffee, which means coffee was brewed and then freeze-dried. The resulting granules can then be put in hot water to create a coffee drink (although some fundamentalist would dispute the claim that the result qualifies as “coffee”, but I digress). Think of it as the coffee-equivalent of a bullion cube. If you put that in your machine, you would - at best - get a weird result and possibly damage it.

What you need for the Moka (the kind of stovetop espresso maker you got) are real coffee beans. Either you get whole beans plus a grinder or you buy pre-ground beans. Some will frown upon the latter, but if you are totally new, it should be ok as a start and I recommend it. Read the labels, because ground coffee comes in different grind sizes, but mainstream Italian coffee brands like Lavazza, Illy, Segafredo and the other usual suspects will for example put a little symbol on the packs showing a Moka like yours, indicating a suitable grind.

Apart from that, follow the instructions that (hopefully) came with your coffee maker, e.g. fill the bottom chamber to the fill line (or just under the valve if not line is given), fill the coffee grounds chamber (the funnel-thingy) flush, but don’t compress, remove from the heat when it starts making gargling noises...

The Nescafé is the same as the one-serving sachets you mentioned before, so if you are ok with that, you can still use it up when you don’t want to pull out the Moka. Although I suspect once you have come to appreciate a good coffee from fresh beans, you won’t want to go back to instant.


What is the history of coffee? I'm a coffee addict and curious about coffee. My question is as follows:

The word coffee comes from? When was coffee discovered? Who have discovered the coffee? Who are the figures and from which countries the coffee is brought to the Asian continent?

Disclaimer: The great article of Reginald Smith's "A History of Coffee" is a must read for everybody who has interest.

One of the stories of coffee's discovery, which is more common than others is as follows: Kaldi, a monk and a goatherd, sees his goats gets excited after eating some berries. Then, prepares the coffee from the beans of the berries.

The second, less common one is as follows: Yemeni priest Ali bin Ömer banished to the mountains of Yemen. There he discovers the beautiful flowers of the coffee tree, then the beverage.

Etimologically coffee roots from Arabic ḳahwa (قهوة). The root of Arabic word is unknown, but some say that it is originated from some poetic form of a word for wine as it is forbidden in the Arabic world. This name is more or less similar all around the world today: Turkish kahve, French cafe, Italian caffe, German kaffee, Dutch koffie, English coffee, Latin coffea.

The wild Coffea arabica is known to be cultivated in Harar valley of Ethiopia at earliest AD 850.

The beverage stayed local for a while, then became known among Arabs. East Europe became aware of it through Ottomans; Especially Austria and Italy. Then, the rest of the world.

Coffee was a very valuable asset even in those years. Therefore, strangers were not allowed to access green beans for long in the Arabian peninsula. Baba Budan, an Indian Pilgrim, was the first one who can manage to take out seven coffee seeds out of Mecca to Mysore strapped to his belly. Then, cultivation out of Arabian Peninsula and East Africa boomed.


Coffee too less for Frenchpress I am new to frenchpress coffee and love the rich flavour of coffee it makes. However I am not sure if I am doing it right. The coffee beans I had grinder packet says 7g of coffee in 180ml of water.

When done properly, it makes less than a quarter of a standard mug.
Is it ok for me too add more grams of coffee with additional water to equal amounts?

How would I know if this is too much strong and can be dangerous because the more grams I put in the more stronger it get. Plus 7g and 180 ml of water won’t let me push down the bat of frenchpress as it’s so low water so it is already on bottom.

The instructions have poor wording, instead use 7g PER 180ml of water, and make as many cups as you like / your french press can hold.

Personally I use an 8 cup french press, I use roughly 50g of coffee, and fill with water high enough to be full when in full bloom (about 30 seconds after you add water and the coffee is expanding, and letting off c02) After about 45 seconds, I give it a quick stir, and top the french press up with about another ounce or so of water and cover for 4 minutes.

The ratio of coffee per water is a suggestion ONLY.  Typically I recommend 8-9g per 120g of water (If I recall, SCAA standard is 9g per 120g water?)  Use it as a starting place, and adjust based on your taste, and how much coffee you want to brew.

Just a note, I go lighter than my suggested ratios in a french press because it brews stronger.  The 8-9g works well with a drip brewer.

Oh.. one other thing!  You are going to have a hard time making dangerous coffee, unless you consider tasting bad dangerous, so don't worry about it being a risk if you are adding too much coffee.  If you stick to the rough suggestions in this post, and other comments on this thread, you are going to get in the ballpark of where you are wanting to go, and then you just fine tune to your personal preference.  And if you manage to make truly dangerous coffee.. make sure to repost the recipe.. I think I could use some of that right about now!!


Difference between steam wand and aeroccino frother I often use an Aeroccino automatic milk frother that comes with some Nespresso machines. It froths milk by whisking it rapidly in a heated cup and produces a rather pleasant foam, though the resulting taste and texture is noticeably different from what I usually get at commercial coffee places.

I don't know whether it's mostly due to some difference in the froth or the fact that I'm not using actual espresso (I use either a Nespresso machine or an Aeropress depending on where I am at the moment).

Anyway, the froth does seem different, but what is the difference, precisely?

Another difference is that the Aerocinno tends to produce firmer and longer-lasting froth compared to a wand. It's designed to provide a one-size-fits-all solution for consumers accustomed to automatic machines, whereas a milk wand requires more skill to use but allows for a lot more customization. Think of it like an automatic vs manual transmission.

Note that the type of milk you use can also make a difference. Keep this in mind when comparing the two.


How fine should I grind coffee for drip/pour over coffee I manually grind coffee beans for drip coffee but I thought that depending on whether the coffee is intended to be used for a cafetiere or espresso machine then the fineness needs to be varied.

So what is the optimum fineness for drip coffee?

Does it matter so much given that I am not using pressure (typically 15 bar in an espresso machine) to force hot water through the coffee grounds.

In general consistency is more important than a specific setting.

The key is that you can actually control both the size of the grind and actually achieve a homogenous grind allowing you to increase the consistency in the coffee when you brew it as you can assertively control the service area being exposed during the brewing process. Since you stated that you have a burr grinder you are off to a great start. There is no defined, agreed upon coarseness of grind for pour over coffee, but I would definitely say that you would want a courser grind than you would for espresso. Experiment to find the sweet spot by making sure you use exactly the same water, coffee bean roast, and number of beans (and thus volume) between different grind settings to find what meets your flavor best.

If you are particularly worried about "getting it right" or do not want to do a ton of experimentation an easy and quick way to jump to a grid would simply to go to a coffee shop, buy a bag of whole beans, ask them to grind it and query them for how coarse of a grind is.


How to keep the time before coffee get out of the machine? I just bought a Nuova Simonelli Musica + Eureka Mignon, so I'm practicing extracting a shot.

I am trying to make the extraction lasts 25 sec.

But when I start the extraction, I first have preinfusion time that last like 3-5 sec, and then the pump starting, that is lasting like 3 sec also.

So, at what time should I begin to count 25 sec ??? At the beginning ? After the preinfusion time ? Or when I see expresso out of the machine ?

Together with the first drop

That 25 seconds we curved in our brains is mostly related to the speed of the extraction. Mostly, under normal circumstances, with a single spout portafilter for a single shot espresso, we expect to see 1 ml per second extracted coffee. At the end, you collect 25 ml's of coffee in your cup.

So, I suggest you to count the time after you see the first drop.


What's the difference in between the red Bourbon and yellow Bourbon? I have ended up three different Bourbon varieties as beans; yellow, orange and red. Are they the same variety, just cultivated in different times of the maturity of the coffee cherries? Or, are they three separate varieties with separate cherry color when they are mature?

They are different varieties (at least 2 of them, red & yellow)

The original Bourbon was the Red. Founded in the Bourbon Island (now Réunion) near by 1790 aprox at carried it by the French to Africa and America (Brazil).

Then, in 1930, a natural mutation of the (Red) Bourbon was found at Sao Paulo (Brazil). This one:

  "Is thought to be either a natural hybrid of Red Bourbon and Botucatu Yellow or a natural mutation of Red Bourbon"

The Orange, it's just another mutation. But I'm certain that is not a ripeness matter, it's a mutation/evolution thing.


Difference between Brew and Keep Warm? I'm wondering about the difference between brew mode and keep warm mode in drip coffee makers. After my Black and Decker 2020B finishes brewing, it keeps the heating element warm for 2 hours. Is that different than if it had simply continued to brew for 2 hours?

If I want to reheat my coffee after the keep warm period has ended, is there anything wrong with simply turning it on  to brew? Would that be the same as the keep warm period and thus be fine, or would it cause the heating element to behave differently and possibly burn the coffee or cause a fire hazard?

Thanks!

Normally in a drip coffee machine the 'brew' mode is where the water in the reservoir is boiled/heated and dripped over the ground coffee, before passing through the filter and into the jug. The 'keep warm' part is usually a hot plate under the jug which heats the jug from below, keeping the coffee warm.

My drip coffee machine doesn't allow you to switch it to one mode or the other, you just switch it on and it pumps the water through the filter until its empty - there is a floating switch in the bottom so it knows when there is no more water left, and the hot plate is always on.

I assume that your drip coffee machine works in the same way but has separate controls for the brew and keep warm features. Switching the 'keep warm' feature back on isn't going to harm anything - I'd question the quality of the coffee after 2+ hours sitting on a hot plate though.


Disadvantages of coffee? I drink coffee many time a day; you can say I'm an addict.  Not for a specific reason, I just love the taste.  My family keeps telling me to stop drinking it, but I can't.

Can anyone tell me the disadvantages of drinking coffee?

The only disadvantage that I see from drinking coffee is that you don't have the time to drink tea!

At the age if 68, I average 6-8 cups of coffee daily,  and have done so for the past 50 years or so. My current job,  I got bored  with retirement,  now averages 35 - 40 hours per week involving continuously standing,  bending,  stretching,  and walking an average of 10 miles a day pushing loads up to 300lbs at a time.

Oh,  the last cup if coffee is right before bed.

If your family keeps nagging you,  take away their soft drinks and cigarettes,  then let them REALLY complain.


Do flavoured coffee beans need to be brewed at a different temperature? I have in the past seen flavoured whole coffee beans on sale. Here is an example (though it was a roadside market stall where I saw them).

Do you need to brew the coffee at a lower temperature, or otherwise prepare it any differently than you would do with unflavoured beans?

Here comes an unintentionally snarky answer:

Flavored coffee and high quality coffee are rarely synonymous. Since flavored coffee masks the organic and natural flavors of the coffee itself, it's rare that a quality bean is used in the first place. Imagine ordering a Glenlivet 18 with Pepsi.

Ergo, I'd say that your brew temperature with a flavored coffee isn't extremely important. In the end, you're really just going to be tasting artificial (natural if you're lucky) flavors that cover up the taste of the bad coffee underneath.

What I would say, however, is before you start using quality coffee after using flavored coffee, be sure to clean your equipment thoroughly. The flavors used in those coffees have a tendency to stick around long after they're gone.


Do I need to boil the water before using my moka? I was recently told that I could improve the flavour of my moka pot coffee by boiling the water separately before putting it in the pot and assembling it.

The theory goes that this means that the pot spends less time on the stove, meaning the grounds are less likely to be burned from the heat of the pot before the water has a chance to turn into steam and brew the coffee.

Is this true?

It is true.

Preboiling the water will make the coffee tastes a lot better. It will reduce the bitterness and give space for a lot of other notes.

Heating up the Mokka too much releases also metallic taste from the machine itself and you boil the coffee.


NS Oscar II should I drain the boiler before storage? I' have a Nuova Simonelli Oscar II machine for events. There is considerable time between those events and I was wondering if I should drain the boiler before storage.

The usual storage time is about 6 months or longer.

Or what are the possible issues that may raise from draining / not draining the boiler.

Thanks

The Oscar 1 has a brass plug that can be removed with a wrench. You can then pick the machine up and tip it over a drain. Some water might remain in the heat exchanger and tubes, but that will get almost all water out. I don't know whether the boiler design on the Oscar 2 is the same, but it wouldn't be surprising.

If there is any possibility of storage temperatures going below freezing, you must drain it. I would drain the machine regardless.


What is the range of ambient temperature I can keep my espresso machine at? Background
I have a Rocket R58 and I'm twondering if it would be safe to keep it in a low temperature place like a garage. Let's say that would be something like 12C. I've had a look around at both the manual for my machine and several others but I can't see any instructions beyond guidance around storage temperature.
For that they mention that it's important to not let it freeze which is sensible and pretty obvious. I've also had a search around google but can't find anything around operating temperatures.
Question
Do any coffee machines have explictly stated safe operating temperature ranges and if so what are they? If this isn't common, have any of you used espresso machines in colder environments longer term and are there any issue involved / is there anything I should look out for?

Any coffe machine is quite broad. I suggest considering the materials involved. Since portafilter machines are meant to operate on higher than ambient temperatures for a very long time, lower temps aren't usually a problem in terms of degradation.
I can't remember any materials involved in a portafilter machine that would degrade faster (or et damaged) in lower temperatures rather than operating temperatures.
Dependig on the age, there might be hemp sealings in the machine that could potentially dry out.


Does anyone have experience with this brewing method? The question here is about the following primitive method for making coffee. Having used this method for many years now I think it gives consistently good coffee, comparable to that from a good espresso machine but without the need for machinery or paper filters.

Recipe: Bring one cup's worth of water to a boil in a small pot. Add about a scoop and a half of ground decent-quality beans to the pot. Swirl gently until chalky bubbles appear. Filter through a tea strainer into a cup. Let stand briefly.

No need to grind the beans to a powder. The tea-strainer gets most of the grounds and the amount of sediment in the cup is about the same as in cafe espresso. The only electric component is a coffee grinder. Using pre-ground beans requires more coffee per cup, as some flavor will be missing.

In general this method produces coffee that is slightly weaker than espresso. While I might add a bit of sugar to espresso to counter bitterness if the beans are old or mediocre, the strainer method above gives coffee that is very drinkable without sugar.

It sometimes surprises me that this simple method isn't more widely used. Has anyone else tried it? Are there any drawbacks to this method? It isn't worth much commercially because it only makes decent coffee one cup at a time.

This method is adapted from one I saw used by fisherman in Brazil, except he used a sock instead of a tea strainer. Comments welcome.

The biggest drawback is that you might add the grounds to too hot water. Especially avoid adding the coffee to water that is still boiling. Wikipedia has some references about the temperature and it states that boiling water will extract bitterness instead of aromatic oils. So just make sure to wait a moment after taking the water off boil.

Second drawback is that since the grounds remain in the pot in contact with the water, you have to empty the pot entirely once the coffee is "done". Leaving the grounds in contact with the water for longer times will only add betterness to the coffee. Of course this is no problem if you only make one cup, but prepare to have a (pre-heated) container ready if making more cups.

Related to the second drawback is that the extraction will continue in your cup because of the sediment, but in my opinion most people will not even notice it affecting the cup.

Coffee oils make it to the news from time to time. Since this coffee is not paper filtered it contains more oils. Some like the taste, some do not. Some link coffee oils to cholesterol levels (I do not..), which might be a personal drawback to some.

Offtopic: the method you describe is actually how my granny makes coffee, with a little twist (that I dislike). After adding the grounds, she heats the water to boil again and quickly removes it from the stove after first signs of boiling.

Edit: Just wanted to mention that none of the drawbacks I listed is unique to this method.


How can I make french press coffee taste less acidic? Is there a trick to making coffee, particularly french press, taste less acidic?

Without any more specific information about the coffee you use and what recipe you use for the french press, we won't be able to give you a specific answer with a solution to your problem. However too acidic probably means that your coffee is underextracted. That means the water hasn't had enough time or wasn't hot enough to extract the flavor compounds you want out of the ground coffee.

There are a few variables that will influence extraction with french press. I already mentioned time and heat. A recipe that I have used with very good results is 6g coffee per 100ml of water, ground to the size of coarse salt with a steep time of 4min. At first you only add a little water (just off the boil), twice to three times the weight of coffee grounds and let sit for 1min. Then give it a stir (there will be grounds on the top forming a crust), add the rest of the water and wait until 4min. Plunge and immediately transfer your coffee to a preheated vessel, either your mugs or a jug. Important here is that you don't let the coffee sit as it will continue to extract and taste bitter after a few minutes.

This should give you an even, full bodied extraction. If you feel like it's still too acidic, you could vary the variables involved. If you grind slightly finer the extraction will be higher. Same thing if you increase the brew time a bit. I suggest you just play around and keep in mind that these variables are not independent of each other. Finer grind means faster extraction for example. With a basic understanding of how extraction works you should get the hang of it quickly.

If the coffee still tastes too acidic although you have tried all suggestions check if the roast is too light, since light roasts tend to have more acidity. Also the origin of your coffee is a factor, african coffees (there are many different regions and processing methods so this is a big generalization) tend to be more acidic, while sumatran coffees are considered the least acidic. Central and South American coffees will often have acidity levels in the middle range.
It might also be sour because the coffee is stale (around 4 weeks after roasting for whole beans, much much much faster for preground) or it might just be shitty coffee.

This is a good little intro in the world of extraction (or rather which tastes are associated with different levels of extraction):
Coffee Extraction and How to Taste It.

This is a very nice little graphic with explanations that helps identifying which extraction problem you have and how to solve it:
The Coffee Compass.

Cheers and enjoy a nice cup of coffee.


How are coffee beans differentiated? Tea grown in Sri Lanka is classified by elevation into high, mid and low grown tea.

High: rich in flavor
Mid: blend of flavor and aroma
Low: rich aroma

Does coffee has such differentiation? If so what are they?

It is important to have in mind that altitude is not the only feature that allows one to differentiate the coffee beans. Temperature is perhaps even more important (altitude influences in the temperatures suffered by a coffee plant, but not all the same altitudes mean the same temperature profiles).

As a brief summary (taken from [1]), we can say that:

Lower elevations (Robusta species) mean a more intensely coffee flavoured bean (more caffeine).
Higher elevations (Arabica species) mean more acid and complex taste.

So, the main factor is the species of coffee. The elevation and temperature only tell you what of the varieties of these species you can successfully grow and how you can harvest it.

According to this source [2]: The Effect of Altitude on Coffee Flavor, that relates only to the Arabica species, can be summarized as follows:

Altitude contributes to a coffee taste profile.
Ideal growing conditions for the coffee tree:

At the coffee belt (a band extending approximately 30° north and south of equator).
At high elevations, between 3,000 feet (914.4 meters) and 6,000 feet (1828,8 meters) and beyond.
These conditions provide a frost-free climate.
Averaging 60°F (15.56°C) to 70°F (21.11°C) year round.

Cooler mountains provide a slower growth cycle for coffee tree.

This means deeper and more interesting flavours (due to a longer maturation process).

Better drainage of soils means less water in the fruit.

Further concentration of flavours.

More fertile the soil, the better.

A volcanic soil is often preferred.

The farther we are from the coffee belt, the less elevation we must grow coffee tree in order to avoid low temperatures.

As a more specific summary:

Generally speaking, more elevation implies a more pronounced and distinctive flavour profile:

From the simple, mild and subtle of those grown at 2,000 feet (609,6 meters).
To a fruit, spice, floral profile for those grown at 5,000 feet (1524 meters) or above (when possible).

This other source [3]: Bean Basics: Planting & Growing Coffee deals with how altitude affects the planting and harvesting of coffee tree, not about its features.

[1]: What’s So Important About High-Altitude Coffee?
[2]: The Effect of Altitude on Coffee Flavor
[3]: Bean Basics: Planting & Growing Coffee


Moka pot - oxidization, rust or mold? I'm using a Tescoma paloma moka pot (aluminium) and after three years (and one mistake made by a friend of mine - tried to clean it with detergent) I noticed a build-up of two things:

White spots that looks like oxidization (also they disappeared after brewing water with lemon)
What can be seen here

that they are not removed after brewing or washing with water.

I read the other similar questions but I'm not able to guess if this is oxidization or something that I should be afraid of. What is your opinion on that?

You have mentioned that you've seen similar questions but... Did you see this one?

What are these spots on the inside of my moka pot? Do I need to remove them?

If yes, then I can help you with two things. First, rust is not possible as your moka pot is aluminum. Therefore, only aluminum oxide and mold are the two options left. Second, if you can remove it, it's mold. Otherwise, it's oxidation and does no harm.

How to remove mold? Bleach is probably the easiest option of you really rinse well afterwards.


Why do coffee packs have an aroma hole if it is recommended to store coffee in an air tight container If it's recommended that coffee should be stored in an air tight container then why do coffee bags have an aroma hole.
Apart from being able to smell the coffee is there another purpose to this? I would've thought that it would be better to not have a hole at all and that it should be air tight.

It seems the hole at the bottom is probably for degassing but I have seen on some packages that they call this an aroma hole.

It's actually a one-way valve & it's critical to the shelf life of the coffee and the preservation of the bag itself.
When coffee is fresh roasted, it releases carbon dioxide. It's basically a by-product of the roasting process. When the coffee is ground, carbon dioxide is released expeditiously. If you simply place fresh roasted coffee in a completely sealed bag, the bag will expand and in most cases rupture.

http://beanfruit.com/blogs/news/15152773-whats-that-thing-on-my-coffee-bag


Would drinking excessive coffee reduce blood hemoglobin content? Would drinking excessive coffee, such as 4-5 20oz cups (100 fl.oz. / 3 L total) per day, reduce blood hemoglobin content?

Are there other digestion or gastric issues related to drinking excessive coffee?

coffee reduces iron uptake. parts of hemoglobin are comprised of iron. if hemoglobin becomes low the oxygen rate to other parts of your body decrease. causing low energy and fatigue. the low iron could also cause anemia.


What are coffee flavorings found around the globe? Recently I learned that in some Middle Eastern countries they add cardamom and cloves to their coffee to flavor it.

Are there any other coffee flavorings found around the globe I might not have heard of?

I prefer my coffee flavored just with water. However, it is common for people to flavor their coffee with many other ingredients with respect to their personal preference. As personal preference is closely related to culture, yes, you may enlist some location-based flavoring ingredients for coffee.

In Turkey, generally, coffee does not have any ingredients except sugar. In the west part, mastic is sometimes added for flavor. This is a common tradition with Greeks, I assume. In the Southeast part, cardamom is rarely added. This is a common tradition with Syrians, I assume. I never heard of cloves around here.

Sugar and its close relatives: I think this is the most common one, independent from the geography.

Milk may be the second most common one. Mostly used in the Italian-influenced Western coffee.

Chocolate is only common in the Austrian-influenced coffee recipes, I assume.

From now on, I think we may say not very common flavorings.

Cinnamon is common both on Austrian-influenced coffees and old-style coffees.

Mastic is common around Aegean Sea with Turkish brewing method.

Cardamom is common around Syria with Turkish brewing method.

Cloves is common around Arabian Peninsula with Saudi brewing method (say, a brewing method close to Turkish).

Chicory is common in Vietnam, South India and in New Orleans/Southern Louisiana of USA.

Butter is common in East Africa, Himalayas and very recently in North America under the fancy name of "bulletproof".

Coconut and Marjoram are my recent encounters in some old Turkish recipes together with Cardamom. Especially, when the beans are ground in dibek, an ancient Turkish coffee mortar.


How should I start a coffee export business? I am from Yemen, one of the world's best location for coffee.

I want to start the coffee business and start a coffee export business but I have no experience in exporting and no customers to export to. Can somebody help how to start this coffee export business? What should I know and how to start?

I am good with business (export process and LC and so) but I have no idea who buys coffee and how to approach them?

Please help.

As another dimension, I see a few trends that you might wish to consider.

Green beans. More people are getting into home roasting, and green (processed but un-roasted) beans are the vehicle. Also, green beans store better for longer time (e.g., freezing) so you can capture a particularly good "year" or crop of beans for a longer period of time. Even whole, unprocessed cherries might be an interesting notion.
Skins and pulp. People make beverages out of the (usually discarded) fruit skin and pulp, called cascara, qishr, or other names. These are difficult to find dried, and perhaps impossible to find fresh.
Direct marketing. Another trend is (broadly) the "farm-to-table" strategy, where roasters or cafes will purchase beans directly from farmers. There might be good business in brokering "direct" deals like this, by helping responsible farmers with good beans get good prices by selling directly to the end user (e.g., a local roaster) instead of through an aggregator or warehouse. You could seek out some exceptional beans with unique qualities and get those farmers into the specialty direct trade market.

Just a perspective from a "consumer" standpoint.


Why does coffee taste better out of ceramic cups compared to a paper cup? I usually drink double espressos and they always seem to taste much better out of a ceramic cup compared to take-away paper cups. I ordered 2 back to back from the same shop within half an hour yesterday, one in a ceramic cup and one to go (I have a coffee drinking problem...) and the difference was still there - so same barista, machine, beans etc. Why is this? For sushi you are told not to eat it with a metal fork since it will supposedly taint the taste, so could this be similar?

Both cup material and temperature are in play here, I think.

A big part of the coffee taste (and experience as a whole) is the aroma. I personally find that paper cups (not surprisingly) smell and taste like paper. Ceramic (or glass, porcelain, etc.) should be practically neutral. Any smell you get from the cup could affect the perception of taste of the contained beverage. If the cup has a plastic lid, that could contribute both to its own smell, or holding-in / reducing the coffee aroma that you smell, also. (Aside: there are some interesting links to the physiology of smell and taste interplay at the Wikipedia article on taste.)

The very experience of drinking from a paper cup versus a ceramic cup is different; heft, shape, handle, other aesthetics, etc., though this probably reduces to personal preference.  For example, I find sometimes that my lip sticks to the outside of the paper cup, which is unpleasant (to me, anyway :). A plastic lid could be a factor here as well.

Temperature may also be a factor. For example, temperature can affect the perception of bitterness. A properly pre-heated ceramic cup/demitasse will help the brewed coffee be at a consistent temperature (without shocking it after pull) and keep it warmer for longer (so it doesn't cool down too quickly). Such temperature changes could result in a difference in taste; keeping brewed coffee at a consistent temperature is recommended -- that and some other general properties are listed here. Temperature stability of the brew will probably be different between paper and ceramic.


What causes the mouthfeel from a French Press? The taste of a well-made French Press-brewed cup is made complete (in my opinion) by the velvety, full-bodied richness that can only be described as "mouthfeel". Which aspects of this brewing method cause that quality to be highlighted?

More of the oils in the coffee remain as opposed to being filtered out. The coffee sits in the water, nothing is filtered out. The plunger leaves the oil in the coffee and prevents the grinds from going into the coffee cup (unless you used a very fine grind in which case the fine particles will go through the filter).


french press technology stalled? Looking at wikipedia, I'm stunned that there are no real technological advancements with the French press.  I've seen the aeropress, and it's interesting, but why has the French press itself not changed?

To begin with, the plunger has multiple pieces, allowing grinds to get between them.  What prevents the invention of a better press?  (I can't imagine much of an improvement to the beaker, outside of using a plunger like the aeropress.)

What do you mean by improve? French press is one of the most popular brewing methods in the world, and rightly so: it's dead easy to operate and produces a great cup of coffee. The mechanism is very simple and easy to clean, a good french-press pot will last years if not decades, and if any part of it breaks it's cheap and easy to replace.

What improvements might you make in general? Control over the brew is probably the most important, and with French press is there really anything you could add? The plunger separates the grounds and the coffee very effectively in a good pot, so not much room for innovation there. The other main variables: grind and timing are beyond the scope of the actual pot. In terms of maintenance and ease of use, the pot is optimal already too.

One could argue that the Aeropress is an improved French press, since the brewing method is similar, especially if you use a metal filter. But it's more of a faff to use, doesn't scale so well (you can get 12-cup Cafetières), and tailored much more to the coffee enthusiast than the average person who just wants a cup of what the know and like.

TL;DR A cafetière is already optimal for making French press, there's no room for significant innovation, beyond inventing new ways to brew coffee.


How much does the shape of the drinking vessel change the flavor? Within wine there is a huge array of glasses for different wines with the believe that different wines taste better out of different glasses.

This can also be seen (though to a lesser extent) with different beer mugs and even root beer (in the classic A&W mug).

How much does the flavor of coffee change based on the shape of the drinking

According to my "Lavazza Barista Guide" the shape of the cup affects the foam of the espresso and indirectly affects the taste.

It is explained as; the foam helps to protect the valuable ingredients to not to be evaporated easily. Also, the foam keeps you espresso warm while you are not drinking it.

In the guide, it is stated that the thickness and the vertical angle of the lavazza cups are specially designed for best coffee experience. So that, at each sip you drink some of the coffee and a bit of the foam and the remaining part of the coffee and foam fits to the now norrower part of the cup.

This sounds like a bit advertisement and a bit reality in a manual prepared by a commercial company. Quite expected in my opinion.


Does coffee raise cholesterol levels? Altering cholesterol is just one of the ways your daily cup of coffee affects your body. If you have elevated LDL cholesterol, should you cut down on your coffee?

Coffee does not include any form of cholesterol, as it is produced in the liver of animals.

However, some alcohols in coffee affect how cholesterol metabolizes in human body. Thus, indirectly affects cholesterol levels.

Extraction of these alcohols are mostly related with grounds contact period with water. So, we can say you should take care about the brewing method.

For example, cold-brew increases the cholesterol levels the most. Drip-brew and instant coffee the least. Turkish coffee increases a lot. French-press increases quite much. Espresso is somewhere in the middle. Pour-over filters are increasing just a little.

More information


What type of coffee maker creates the most coffee scent? I stopped drinking coffee for a while but recently picked it back up, mainly because I enjoy the scent.  Previously I had a Keurig machine; convenient, but produces almost no smell during brewing.  Until I broke it a couple days ago, I was trying out a french press.  Again, very little of that heavenly wakeup scent.

What method of coffee making will best fill the house with coffee scent?

If you want a lot of scent, you will want to make sure that nothing stops evaporation - so no lid and a large surface area are paramount.

The classic method would be hand-filtered pour-over, which system you choose is up to you, famous examples are Melitta, Chemex or Hario (which all follow the same principle). And as an additional benefit you get to enjoy the aroma right there while you are brewing the coffee.

An alternative could be Turkish mocca, where super-fine grounds are boiled. The boiling process will likely create more steam, on the other hand, the surface area of a cezve is a lot smaller than that of a filter. You will also have a quite different end product and have to decide for yourself whether that fits your expectation or not.

And in any case, I recommend grinding your beans fresh just before brewing, you’ll be surprised at how much of a difference that alone will be. And grinding also releases the coffee smell you are aiming for.


Office bean-to-cup machine tastes acidic in the morning In our office we have a bean-to-cup machine. The rate at which we use it means we always have fresh beans - generally it tastes pretty good for machine-made coffee. However, first thing in the morning, just after turning it on, the first few coffees can taste very acidic indeed. Is there any potential remedy for this other than throwing away the first few coffees?

My thought is that once you turn on the machine, the machine starts to heat the water. Often the heating system is regulated by a PID regulation (Maybe on-off regulation). The machine will heat the water fast to make sure you can get your cup of coffee:) Once the water is heated it will stabilize to the intended temperature. If the water is heated above the intended temperature it will cause acidic compounds to be extracted from the beans. After a while the temperature is stabilized and you will experience that the coffee is no longer acidic.

Another theory is that the pipes within the machine are not clean.

You can test both.

Try turning on the machine an hour before making the first cup. If this helps it is probably a temperature issue.

If not try to clean the machine by running through hot water before making the first cup.

Hope one of these solutions will help you with your issue.

"Life is too short for bad coffee"


Why does espresso taste different to percolator coffee? I recently switched from percolator coffee to espresso. The taste is noticeably better. I feel as if it is common knowledge that espresso coffee is superior to percolator coffee. Why is it different? What are the scientific reasons for this?

Espresso tastes different than percolator coffee, but not necessarily better.  Espresso extraction produces a more concentrated drink with a different set of compounds that you would get with percolator extraction.  With a shorter extraction time and higher pressure, espresso will have a slightly different set of compounds than you would get from the same coffee with percolation.

Some people prefer a more concentrated taste, however, some do not (many people think espresso is "too strong" when drank straight, thus the popularity here in the US of mixed espresso drinks).  This doesn't mean it's necessarily better.  Some types of beans are not well suited to espresso extraction and will actually produce a better cup when brewed with other methods.

All coffee can be benefited or hindered by brew/prep method, but the quality of the bean and it's roast have quite a bit of influence in the matter.  Badly grown, processed and roasted coffee will not magically be made better by espresso extraction.  It might actually end up worse because concentrating it can highlight it's flaws.


What is "mırra", the over-brewed Turkish coffee? There are many methods mentioned in Coffee SE on Turkish coffee brewing. Are there any other alternatives/variations from the standard way of preparing Turkish coffee? One of such variety I have heard of is the bitter flavored mırra.

Mırra is a specialty Turkish coffee brewing variety that's known to be very bitter.

The beans are roasted very dark to prepare the bitter possible coffee flavor.

Furthermore, during Turkish brewing process, the grounds are boiled* for minutes (and legendarily up to hours) to produce a bitter flavored coffee.

The end result is a very dark and intense beverage which can be consumed in very small amounts in small cups.

Mırra is not very common and mostly can be found in the southeastern part of Turkey and in some nearby Arab countries like Syria or Lebanon.

(*) On the contrary of the standard Turkish brewing method


How to follow Aeropress instructions when water filters through too quickly When I try following the Aeropress instructions (2 scoops coffee, fill to level 2, stir for 10 seconds, press for 20 seconds), I find that all the water has filtered through before I get to even 10 seconds of very gentle pressing.  Most of the filtering takes place while I'm still stirring.

Am I doing something wrong?

I'm using pre-ground coffee (Tesco decaf).

It sounds as though the pre-ground coffee you are using is not ground fine enough. Generally the more coarse the grind, the faster water will filter through.   You may try throwing some additional grind on your coffee, or buy pre-ground coffee that is more finely ground (although a snob such as myself would never actually advise buying pre-ground coffee).


Best practices for reheating coffee By the time I come home from work in the morning, a pot of coffee that was brewed by others in my house (and is still quite full) is slightly too cold by the time I am able to drink it. I don’t want to waste the resources or time brewing a fresh pot, but the coffee always tastes “off” when I microwave it. The flavor is also much worse if it is reheated after cream is in it, but even black coffee leaves much to be desired. What are the best practices for reheating coffee?

Cold-brewed coffee heats well. Hot-brewed coffee that is old (whether on the warmer for hours or allowed to cool) will have pronounced flavors that most drinkers find unpleasant.

If you are concerned about wasting grounds, either brew smaller batches of hot-brewed coffee, or look into cold-brewed coffee. Most groceries carry pre-made cold brew or cold brew concentrate (read the labels to see if added water or milk is recommended), or consider getting a brewing container to make at home in the fridge. It stays good for 7-10 days once brewed so you can purchase or make a week's worth at a time.


Is there a name for this Americano/Long Black Variation? I am quite sensitive to caffeine so when brewing espresso I want to extend the enjoyment of my drink. An americano to me is way too much water and I lose a lot of what I think makes an espresso amazing. No water added and I drink the coffee too quickly and find myself wanting another. This is my new recipe: to help extend my drink. I brew a standard double espresso of about 36-40g and add that same weight in water. If I made a 40g espresso I would add 40g more of water. I think of it like a cortado but instead of milk I use water.

I am wondering if this is an actual drink and if it has a name or if it is just some crazy successful experiment I made up.

I mostly drink Americano's  at my favorite coffee roaster, Kaladi Brothers Coffee, ( barista's take a two week training before they are allowed to pull shots for customers ) but occasionally i get a Stretched Lungo. ( French Press Exclusively at home )

Lungo

The link will educate you as to the particulars of the Lungo.

  Both lungos and Americanos are made using an espresso machine and
  water. Which makes you ask ‘Is a lungo an Americano?’. The method of
  making both these coffees sounds the same, but there is a big
  difference. When you make a lungo, all of the water is brewed and it
  generally comes out shorter than an Americano.

  When you make an Americano you add the water after the espresso has
  been pulled from the espresso machine. Americanos also usually come in
  larger cups so you can add as much water as you like to the coffee.

  Lungos should be served in a slightly smaller cup because you don’t
  need to add any water after making it. But if you really like, no one
  will probably judge you if you do!

  Both coffees are made with ground coffee and roughly the same amount
  of water. So you’d expect them to taste the same right? Wrong. Adding
  the water after the espresso has been pulled gives you a weaker
  flavored coffee. Having the water pass through the ground coffee
  granules, as they do in a Lungo, gives you a much stronger flavored
  coffee. Great for those of you who like a strong dark coffee to kick
  start your day!


Your recommendation and advice for Turkish coffee blends I am in a process of establishing a small coffee-factory in Egypt.

I would like to know your recommendation for Turkish-coffee-blend, what do you prefer, what are your recommendations ?

I am thinking of (Brazilia-Santos 70% + Harrar 30%) , do you think is it a good combination ?

Thanks very much

I still think this is very subjective. Still, some facts may help.

Brazilian Santos is the most commonly used beans in Turkey for Turkish coffee. However, it is not my favorite. Other people may like it a lot. Santos is something like a mixture of many varieties, though its taste may fluctuate a lot with respect to your sources. The main reason that it is used in Turkey is the fact that it is cheap.

Ethiopian Harrar, on the other hand, is one of my favorites. I don't have any concrete proofs but I believe that it was historically one of the beans used for Turkish coffee during Ottoman times, together with Yemen Typica.


Is there any way to preserve roasted coffee beans? I know different people try different things to preserve roasted coffee beans, including freezing them or vacuum sealing them. But do any of these actually work? I have a very rare and expensive coffee bean that I'd like to take out once a month or so on special occasions, and I'm trying to see if there's anyway to do this without buying the coffee new every time.

Coffee beans, once roasted, are perishable; they don't "keep". Within roughly five days of roasting staleness is detectable (taste/quality is adversely affected). There is one way to preserve freshness: consume freshly roasted beans within roughly a week. Don't freeze; beans absorb moisture and lose flavour— ick. Vacuum packs aren't the answer, either. To remove all gases from packaging would require a system using pressure, 29" Hg, that no one, not even coffee giants, can afford. The best practice is to just buy beans (roasted on the day you purchase, ideally) in quantities you'll use within a week to 10 days.


How do I get started in roasting my own beans at home? I'd like to experiment with roasting my own beans at home.

I'd like to keep the equipment requirements as basic as possible. No fancy gizmos or machines. I have a gas stove.

By far the easiest way to start at home roasting is with a hot air popcorn popper.  You can get a used one for $5 at a thrift store or pay approximately $20 new for one.  Or perhaps you already have an unused one laying around.  There are also people and websites out there showing you great ways to modify or make them better with cheap addon parts or hacks.

I started with one and after I decided I was hooked I spent the money on a commercial made roaster, but I learned most of what I know with a hot air popper in my front yard.  I think the biggest issue for stove top roasting is the smoke.  If you don't have great ventilation in your house over your stove, accidental overroasts and dark roasts become a major problem.


How can I calibrate my Hario grinder? I have a hand-held Hario grinder, like this:

The grind is adjusted by twisting a little knob underneath the black upper part. It's very hard to know when you're twisting it how far between the two endpoints you are, since it overturns in both directions, with basically no feedback.

What's the best way to calibrate the grind size? I'm brewing with an Aeropress.

Short answer: Slowly. Binary search. But for espresso, Turkish, moka, or AeroPress: I adjust mine to nearly the tightest (smallest) setting possible that still allows me to turn the crank without difficulty.

Method: This is how I adjust mine.

Approximate the setting by eye. Looking at the burrs, gauge about how large you'd like your grounds to be.
Mark this setting (temporarily) with a wax pen or marker.
Grind a bit of coffee and look at the average grind size; determine whether you'd like it coarser or finer.
Change the setting by N (e.g., 4) steps in one direction.
Repeat. Grind a bit more coffee. If you went in the correct direction (finer or coarser), determine whether you'd like it finer or coarser. (Start over if you went in the wrong direction)
Change the setting by going N ÷ 2 (e.g., 2) steps in that direction.
Repeat the grind and check. Terminate if you're happy, or go one step at a time until you are happy.
MARK THIS SETTING AND HOPE YOU NEVER HAVE TO CHANGE IT ;-)

My experience: I have a similar Hario model (this one), which sounds marginally more difficult to adjust than the one you're talking about. I use mine for almost all of my daily coffee grinding. I set it very infrequently: I go through phases between pour-over and moka, and I try not to go through these phases more than once per month to avoid adjusting this thing.

To adjust my model:

Remove top nut.
Remove crank handle.
Remove setting bracket.
Twist the toothed, threaded washer/nut about the threaded shaft to move the nut up (counter-clock, coarser grind) or down (clock-wise, finer grind).
Replace bracket, handle, top nut.

I mark the "set-screw" nut with a marker to remember where I've tried. I try to avoid going more than one revolution either way; on mine, two revolutions goes from moka-fine powder to French-press coarseness.

When you've figured it out... I have put scratch "marks" on the screw for I (moka: fine), II (drip: medium), III (French press: coarse) so that I don't have to guess quite as much. Highly recommend indelible marks on your grinder once you find the setting you like. To change from one setting to the other, adjust to the middle: then go tighter to the "fine" setting, and looser to the "coarse" setting (otherwise, it can be ambiguous).

Other than changing the settings, I like the thing. There was even a Kickstarter that funded a stabilizing mechanism for the bottom to ensure a more-even grind: it launched as EvenGrind (I have no affiliation with it).


How does Caffeine-free coffee affect your body? Is it caffeine or chlorogenic acid the ingredients of coffee stimulating the stomach?

If it's chlorogenic acid, do you have coffee without chlorogenic acid? Or how to choose coffee with less chlorogenic acid?

In short, love the taste of coffee, but wouldn't the reaction on the body, that is, no diarrhea, frequent urination nor excitement.

I personally couldn't taste any difference between decaf and regular coffee but depends on the brand. According to some resources is decaf the biggest source of antioxidants in the western diet and it has positive impact on health if you drink 2-3 cups per day. From my personal experience, you can drink probably as much decaf as you want since it doesn't have any negative side effects, regarding regular coffee you might get breath problems and high blood pressure if you drink too much. There are lot of good brands of decaf where you don't taste any difference between it and regular coffee.

sources:

https://www.healthline.com/nutrition/decaf-coffee-good-or-bad

https://www.medicalnewstoday.com/articles/325502.php

https://greatist.com/eat/is-drinking-decaf-coffee-better-for-you


How long can we safely store cold brew concentrate? How long can we store cold brew?
Does storing cold brew for a week or more affect its taste or texture provided that we use good grinding beans and make it under proper ratio?

In my experience, if you have sanitised your equipment properly you should get three to four weeks when storing cold brew in a ready-to-drink ratio in the fridge. My feeling is that concentrate would probably have a longer shelf life, but by how much I can't really say.

The taste will change over time depending on how well filtered the cold brew is. If it is only lightly strained or filtered, a lot of coffee solids will remain in the brew and make it stronger/bolder over time (sometimes it can be quite nice). If it is well filtered and clear, then the flavour will be pretty consistent until it starts to go sour or bad.


Is harvest time important for coffee quality? The other day, I spoke to a tea fanatic. he introduced me into tea world and also explained me, that harvest time of tea leaves has significant role in tea quality. (Especially the first flush which is the first harvest in given year)

It made me wonder: Is there any significance to coffee quality regarding the bean's harvest time?

Yes, it does, but it's much more complex than that :-)

Harvest times vary greatly depending on the latitude, altitude and variety of beans being harvested. There is a very large table here which illustrates the variety of harvest/shipping seasons, as well as the optimum points of both.

In general, December-February is best, but some countries vary anywhere from June to October. Some countries with a larger variety of crops have a lot of different 'Best' points, e.g. Kenya:

(The top brown/red line indicates harvest times, Red Bs indicate the optimum harvest times.)


How to get rid of coffee addiction? I drink 5-8-10 cups of coffee a day prepared on automatic coffee machine.

My problem is that I don't have a stimulating effect from coffee. So I usually feel if I must drink coffee or I feel tired If I don't.

I have tried to get rid of this addiction several times. I can easily stop drinking it for a couple of days (or weeks). First 1-2 days I have a headache and I'm tired; but after that I feel normal. After 2 weeks I tell to myself why not to have 1 coffee, then 2 coffee and very soon I'm again on 5-8 cups a day.

Update:
After one year nothing has changed. I'm still on 5-8 cups of strong coffee. I simply like how it smells, I like how it taste.

First, the effects you observe are known as caffeine withdrawal and discussed here.

Coffee addiction is previously discussed here.

However, it is not discussed how to get rid of a coffee addiction. First, you should understand if overcoming this addiction is necessary. I assume, most people who are members of Coffee SE are not likely to think that.

Here is a general link that explains how to get rid of any addiction in three steps:

Decide to quit. (Think positive future effects, write a commitment to yourself,
etc.)
Make a plan to quit. (Set a date, set your environment, overcome the triggers, seek professional help, etc.)
Handle withdrawal. (Fill your time with new habits, keep clear of triggers, don't find rationalizations to start again, celebrate accomplishments, etc.)


Is there a "standard" ratio of espresso to milk in a latte? If I order a caffè latte from a coffee shop, will it always be the same strength? As in the same ratio of espresso to milk? For example, I think I heard that Starbucks UK use more espresso than is normal, though I can't remember if that's compared to "normal for a latte" or the other Starbuckses in the rest of the world.

Or does it vary wildly from shop to shop (and thus I need to learn or ask at each individual coffee shop)?

It varies by shop and order.  For instance, order a latte at Starbucks, you have a selection of sizes, and then variance in the number of shots (or espresso) you order in the drink.  Since the sizes are not doubled (12, 16, 20 ounces, not 12, 24, 36) and half shots are not a thing, the ratio will vary at the order level.


What is the caffeine content in Lavazza brand coffee What is the caffeine content of the Italian coffee LAVAZZA brand?  It is sold at several roast levels, so there is probably some variation.

It is more or less impossible to be precise about this.  The factors involved with dictating caffeine levels of any given coffee bean are numerous, and impossible to define for a single bag of roasted coffee.  Here is Lavazza's answer to your question:

Espresso or mocha coffee 40-80 mg per cup. American coffee 115-120 mg per cup. Instant coffee 65-100 mg per cup. Decaffeinated coffee < 5 mg per cup.

Lavazza Coffee Welness


How would the ratios of iced coffee differ from regular coffee? If I'm making iced coffee, should the ratios of the ingredients (coffee, water, sweetener, milk) differ in any way?

If so, how?

Recipes vary according to taste, but if you want a similar concentration ("strength") of coffee, you'll probably want to use a stronger brew of coffee (basically amounts to using more grounds). This is because you're diluting the coffee when you add the ice (which melts), even more so if you're trying to start with freshly brewed and very hot coffee (melting more ice). Here's a suggestion from Chow and a discussion from Serious Eats that discuss the methods.

Personally, though, I prefer the result of cold-brewed coffee. Rather than brewed-hot and served-cold, it's both brewed and served cold. I think the cold-brew extraction is a better complement to the cold service. Furthermore, less ice might be needed to cool the beverage to a similar temperature, which is an added bonus. See the myriad questions with cold-brew for more on that subject.

As for milk/cream and/or sugar/sweetener, this seems to be entirely personal preference. I take mine black, so I'll let others comment on that.


Roasting my coffee beans I just read online that some people roast their coffee bean before they grind the bean, to adjust the flavor. This sounds really interesting, and I would like to try. I would like to do this properly, and I am wondering about couple of things:

What temperature to use, and for how long? I would imagine that this is determined by the current roast of the coffee and the target roast I would like, is there any kind of lookup table as a guidance?
Some people mentioned cooling and de-gas after roast. What does that mean? I understand the cooling part, but what kind of process is de-gas - I guess it is some process happening on its own as the bean is cooled, but I am curious what exactly it is.

Your first question isn't clear exactly.  All drinkable coffee has been roasted first, as raw coffee beans are not edible. I've read that re-roasting beans isn't practical for some reason that I'm not clear on, but I agree with Peter Pei Guo's, comment about why you would want to re-roast coffee in the first place.

Immediately after roasting, coffee beans produce carbon dioxide gas as a result of the chemical changes happening inside the bean.  This gas takes some time to be released from the interior of the bean, anywhere from 3-5 days.

I've brewed my own home roasted coffee immediately after roasting to see if this is really true, and yes, it is.

Immediately after roasting the coffee has a really harsh, sour taste from the acidity that accompanies carbon dioxide gas (carbolic acid).  It also foamed (bloomed) really violently with the addition of hot water.  After resting the roasted coffee for about 5 days, the coffee from the same batch of beans tasted great.

One of the indicators of freshly roasted coffee beans is the bloom that they produce as some residual carbon dioxide gas is released with the addition of hot water.

As time passes and the beans begin to stale a bit, the bloom lessens, then disappears.  After properly resting freshly roasted coffee however, the small amount of residual carbon dioxide doesn't affect the taste.  Immediately after roasting however, the carbon dioxide levels are too high to allow good tasting coffee when brewed.


Stability of Chemex Filter When I am brewing with my Chemex, most always the filter begins to drag down along the inside, and I always have to use my fingers to pull it back and re-balance the filter. I have tried regular Grocery Store filters (don't remember the brand name), and now I am using Chemex brand filters. Am I doing something wrong?
I have also tried mimicking techniques I see online, they bring up the issue of the filter insulating the Chemex and not allowing open flow; however I have never seen anyone address the issue I face. I would also be willing to change to a Chemex-adjacent piece if it would mean avoiding this issue.

I wonder if you are using the correct filter for your particular Chemex.  On their website that there are basically three styles; halfmoon, circle and square.
https://www.chemexcoffeemaker.com/filters.html
One of these looks to be very narrow and if used in the classic style brewer may cause what you are experiencing.


Why must the milk be frothed? Nearly every coffee machine has the milk go through this device which not only heats it up but causes it to froth up.

Why is this important for a coffee? What's wrong with just heated milk?

It's not that just heated milk is wrong or tastes bad.
It's only that there are some (popular) coffee drinks that uses steamed or frothed milk (are not the same, read this) by traditional way.

On those popular drinks you can find the cappuccino, latte, etc... (as you can see on this infographic), but at home you always can add regular hot milk to your coffee (but we all agree that it isn't feel and taste like the regular way).

Last, why are those techniques important for a coffee? I think that gives a different flavour and tasting to the drink, due to its consistency (and of course, that let you to do some pretty nice latte art)