Every person who has ever opened a bottle of beer knows what happens: numerous bubbles appear and actively rise. If it were carbonated water, the bubbles would burst when they come out, but because the surface tension coefficient in beer is much higher than in water, a large volume of foam is formed.

Beer is poured into the center of a glass from a height of 2-3 cm above the rim of the vessel. After the foam settles, more beer is poured. Typically, a full glass should be three-quarters filled with beer, and the space on top is occupied by the formed foam “cap.” The foam in good beer should have the consistency of cream, it should be solid and compact, with small bubbles and completely white. To better understand this, it is enough to pour beer into a large glass or mug. In this case, the height of the foam should be at least 4 cm and should be maintained for at least 4 minutes. If you blow on the foam and it disappears, it means the beer is of poor quality, but if it holds its shape, the beer is good. Moreover, with good foam, it should be able to hold a coin placed on top of it. Good foam sticks to the walls of the vessel and leaves traces on the inner surface of an empty glass.

Keg beer, due to its naturalness, is always better than bottled beer. Fermentation of residual extract in beer that occurs during the aging of young beer leads to the release of carbon dioxide gas in the beer. To preserve this gas in the beer, the container is sealed – in brewing, this process is called spunding. As a result, unwanted contact of the beer with air is excluded, and pressure is created in the barrel under the action of gas, which, in turn, determines the amount of dissolved carbon dioxide gas in the beer. The higher the pressure in the barrel, the more saturated the beer will be with this important and essential component. Only carbon dioxide gas makes the beer so tasty, so foamy, so stable. If there is too little carbon dioxide gas in the beer, all the taste defects that occurred during brewing become more evident.

The composition and pressure of the mixture are selected in such a way as to avoid excessive carbonation (over saturation with carbon dioxide) of the beer and thereby preserve its natural, clean, and smooth taste. The composition of the mixture depends on the type of beer. While Irish beer “Guinness” is already widely dispensed using “beer gas,” in the pouring of other elite varieties, gas mixtures are used extremely rarely. It should be noted that the increase in the cost of beer when using mixtures is compensated by the refinement and smoothness of the new taste of this wonderful beverage.