question: Why does putting ice cream in liquid cause such big bubbles
comment: It's the butterfat. Fats and oils can spread out into very thin layers, which can surround other components of the liquid mix. When the bubbles pop, the fat is returned to the mix.
passages: Shaving cream is an example of a complex fluid. Without stress, the foam appears to be a solid: it does not flow and can support (very) light loads. However, when adequate stress is applied, shaving cream flows easily like a fluid. On the level of individual bubbles, the flow is due to rearrangements of small collections of bubbles. On this scale, the flow is not smooth, but instead consists of fluctuations due to rearrangements of the bubbles and releases of stress. These fluctuations are similar to the fluctuations that are studied in earthquakes.
  
  Section::::Dynamics.
   Using a whisk on certain liquids, notably cream or egg whites, can also create foams through mechanical action. This is the method employed in the making of sponge cakes, where an egg protein matrix produced by vigorous whipping provides almost all the structure of the finished product.
   Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase. A well-known example of this phenomenon, the "ouzo effect", happens when water is poured into a strong alcoholic anise-based beverage, such as ouzo, pastis, absinthe, arak, or raki. The anisolic compounds, which are soluble in ethanol, then form nano-size droplets and emulsify within the water. The resulting color of the drink is opaque and milky white.
  
  Section::::Mechanisms of emulsification.
   Syneresis (also spelled 'synæresis' or 'synaeresis'), in chemistry, is the extraction or expulsion of a liquid from a gel, as when serum drains from a contracting clot of blood. Another example of syneresis is the collection of whey on the surface of yogurt. Syneresis can also be observed when the amount of diluent in a swollen polymer exceeds the solubility limit as the temperature changes. A household example of this is the counter intuitive expulsion of water from dry gelatin when the temperature increases. Syneresis has also been proposed as the mechanism of formation of the amorphous silicate composing the frustule of diatoms.
   This ice cream soda starts with approximately 1 oz of chocolate syrup, then several scoops of chocolate ice cream in a tall glass. Unflavored carbonated water is added until the glass is filled and the resulting foam rises above the top of the glass. The final touch is a topping of whipped cream and usually, a maraschino cherry. This variation of ice cream soda was available at local soda fountains and nationally, at Dairy Queen stores for many years.
  
  A similar soda made with chocolate syrup but vanilla ice cream is sometimes called a "black and white" ice cream soda.
   Section::::Recreation.:Freezing.
   In this capacity, it is the saponins found in soapberries that allow the formation of Indian ice cream. Like beating an egg white, agitating the soap berries introduces air into solution. Without a surfactant like the denatured proteins of egg whites or in this case, saponins, the air would quickly escape and the mixture would return to a solution. However, by stabilizing the interface of the dispersed and continuous phases of the foam, the air remains trapped in the agitated berry solution.
   Creaming of an emulsion also increases the tendency of an emulsion to inversion. This class of process occurs mainly in special cases, when both the continuous and dispersed phases of an emulsion are liquid, as commonly is the state in dairy cream. It is common where the volume of the two fluid components is about the same or the volume of the dispersed phase is larger than that of the continuous phase. The process of emulsion inversion occurs when the dispersed droplets unite, but retain the formerly continuous material as droplets within the mass. 
   Like in whipped cream, air bubbles are initially stabilized by the protein "β"-casein, prior to their adsorption of fat. This adsorption causes destabilization of the bubbles, because the fat molecules are amphiphilic (i.e. they have polar and non-polar ends), competing with protein molecules which are more conducive to bubbles. The denaturation of milk fat occurs around , so milk at higher temperatures is not significantly affected by this problem. At higher temperatures, the protein "β"-lactoglobulin enables the foam to maintain its structure and is the prime factor in the formation of foam. This can be show trivially by adding various quantities of skim milk powder which contains a high concentration of "β"-lactoglobulin.
   Whipped cream may also be made in a whipping siphon, typically using nitrous oxide as the gas, as carbon dioxide tends to give a sour taste ("cf." soda syphon). The siphon may have replaceable cartridges or be sold as a pre-pressurized retail package. The gas dissolves in the butterfat under pressure, and when the pressure is released, produces bubbles and thus whipped cream.
  
  Section::::History.
   This is an "invert emulsion" or "inverted emulsion", in which the formerly continuous phase has become the dispersed phase and vice versa. Inversion happens in dairy cream when the butterfat concentration is too high, and the resulting invert emulsion looks much like butter. 
  
  Commonly invert emulsions look much like a paste or thick cream, and typical examples are mayonnaise, margarine (especially "low-fat" grades of margarine), similar creamy foods, pharmaceutical ointments, and cosmetic "creams". 
   Creaming, in this sense, is the technique of softening solid fat, like shortening or butter, into a smooth mass and then blending it with other ingredients. The technique is most often used in making buttercream, cake batter or cookie dough. The dry ingredients are mixed or beaten with the softened fat until it becomes light and fluffy and increased in volume, due to the incorporation of tiny air bubbles. These air bubbles, locked into the semi-solid fat, remain in the final batter and expand as the item is baked, serving as a form of leavening agent.
  
  Section::::Poaching.
   BULLET::::2. The second stage involves mixing the incorporated air throughout the milk ("mixing" or "texturing"), which is achieved by immersing the steam wand more deeply (typically 20–30 mm). This creates a turbulent vortex or "whirlpool" in the vessel. This step is necessary to integrate the foam which naturally separates from the liquid phase. During this stage, the milk is also heated to about , at which point the steaming is finished.
   Freezing of small soap bubbles happens within 2 seconds after setting on snow (at air temperature around –10...–14 °C).
  
  Section::::Art.
   When using a steam wand, the volume and type of foam is controlled by the barista during the steaming process, and loosely follows these steps:
  
  BULLET::::1. Air is introduced from the steam wand by immersing only the tip of the wand in the milk. This process is sometimes known as "frothing", "stretching", or "surfing", and usually lasts less than 10 seconds. After the creation of small bubbles, the milk is covered with a soft foam phase which separates from the liquid and floats on top of the milk.
   BULLET::::1. Churning physically agitates the cream until it ruptures the fragile membranes surrounding the milk fat. Once broken, the fat droplets can join with each other and form clumps of fat.
  
  BULLET::::2. As churning continues, larger clusters of fat collect until they begin to form a network with the air bubbles that are generated by the churning; this traps the liquid and produces a foam. As the fat clumps increase in size, there are also fewer to enclose the air cells. So the bubbles pop, run together, and the foam begins to leak. This leakage is called buttermilk.
   Creaming (chemistry)
  
  Creaming, in the laboratory sense, is the migration of the dispersed phase of an emulsion, under the influence of buoyancy. The particles float upwards or sink, depending on how large they are and how much less dense or more dense they may be than the continuous phase, and also how viscous or how thixotropic the continuous phase might be. For as long as the particles remain separated, the process is called creaming. 
   The absence of oil (or the significantly lower oil content compared to traditionally brewed coffee) makes the system more stable and the bubbles do not collapse with the same ease as in cream. Soon after the foam is created, a process of thickening takes place where water molecules are constantly pushed out of the frothy mixture. The water is pushed out due to drainage occurring due to pressure differentials along the foam septum. Higher viscosity will retard the phenomenon, and that is the reason that the addition of sugar will create a better foam. The phenomenon continues until bubbles come very close together and the foam almost solidifies. This process can take between 2 minutes to 10 minutes and depends strongly on the agitation process during mixing. As the bubbles come closer together they will slowly start to coalesce and create bigger bubbles. According to the Laplace pressure equation, variation in bubble size will result in faster collapsing of the bubbles since the bigger bubbles will consume the smaller ones. Hand-mixers create smaller and more uniformly sized bubbles. The smaller bubble size reduces the bubble pressure gradient and forms a much longer lasting foam.
   Just as a teaspoonful of water dropped into a bowl of vegetable oil forms a little bubble of water in the oil, each drop of the alginated liquid tends to form into a small sphere in the calcium solution. Then, during a reaction time of a few seconds to a few minutes, the calcium solution causes the outer layer of each alginated liquid sphere to form a thin, flexible skin. The resulting "popping boba" or artificial "caviar" balls are rinsed then in water and saved for later use in food or beverages.
  
  Section::::Preparation.:Reverse spherification.
   Section::::Mechanisms for protein adsorption.:Biochemical.
  
  While the aggregates can explain much of the protein fouling found in milk processing, this does not account for it all. A third type of fouling has been discovered that is explained by the chemical interactions of the denatured β-lg proteins.
   The phenomenon is explained by the effect of bubble density on the speed of sound in the liquid. The note heard is the frequency of a standing wave where a quarter wavelength is the distance between the base of the mug and the liquid surface. This frequency "f" is equal to the speed "v" of the wave divided by four times the height of the water column h:
  
  The speed of sound "v" in a homogeneous liquid or gas is dependent on the fluid's mass density (formula_2) and Adiabatic Bulk modulus (formula_3), according to the Newton-Laplace formula:
   Creaming is the accumulation of drops in the dispersed phase at the top of the container. This occurs as a result of buoyancy forces. The density of the dispersed and continuous phases, as well as the viscosity of the continuous phase, greatly affect the creaming process. If the dispersed phase liquid is less dense than the continuous phase liquid, creaming is more likely to occur. Also, there is a greater chance of creaming at lower viscosities of the continuous phase liquid. Once all of the dispersed drops are in close proximity to each other, it is easier for them to coalesce.
   The above explanation only holds for bubbles of one medium submerged in another medium (e.g. bubbles of gas in a soft drink); the volume of a membrane bubble (e.g. soap bubble) will not distort light very much, and one can only see a membrane bubble due to thin-film diffraction and reflection.
  
  Section::::Physics and chemistry.:Applications.
  
  Nucleation can be intentionally induced, for example to create a bubblegram in a solid.
  
  In medical ultrasound imaging, small encapsulated bubbles called contrast agent are used to enhance the contrast.
   It can be observed by pouring hot milk into a mug, stirring in chocolate powder, and tapping the bottom of the mug with a spoon while the milk is still in motion. The pitch of the taps will increase progressively with no relation to the speed or force of tapping. Subsequent stirring of the same solution (without adding more chocolate powder) will gradually decrease the pitch again, followed by another increase. This process can be repeated a number of times, until equilibrium has been reached.
   The tiny bubbles within the chocolate form via aerating the molten chocolate with gas, typically carbon dioxide or nitrogen, while at a high pressure, which causes microscopic gas bubbles to form within the liquid. The liquid is then lowered to atmospheric pressure as it cools, causing the gas pockets to expand and become trapped in the chocolate. Air is not used to make the bubbles as this would oxidize the chocolate.
  
  Section::::Advertising.
  