After pouring beer into a glass, jets of small bubbles appear and begin to rise, forming a frothy head. As the bubbles burst, the gaseous carbon dioxide released imparts the desirable flavor to the drink. But how many bubbles are there in this drink? By examining various factors, researchers reporting ACS Omega estimate that between 200,000 and almost 2 million of these tiny spheres can form in a lightly poured lager.
Around the world, beer is one of the most popular alcoholic beverages. The lightly flavored lagers, which are particularly popular, are produced by a process of cold fermentation, converting the sugars in the malted grains into alcohol and carbon dioxide. In commercial packaging, more carbonation can be added to achieve the desired level of fizz. This is why beer bottles and cans hiss when opened and release micrometer bubbles when poured into a mug. These bubbles are important sensory elements of beer tasting, similar to sparkling wines, as they carry compounds of flavor and odor. Carbonation can also tickle the drinker’s nose. Gérard Liger-Belair previously determined that around 1 million bubbles form in a champagne flute, but scientists do not know the number created and released by beer before it is flat. So Liger-Belair and Clara Cilindre wanted to know.
The researchers first measured the amount of carbon dioxide dissolved in a commercial lager just after pouring it into a tilted glass, much like a waiter would to reduce its surface foam. Then, using that value and a standard tasting temperature of 42 ° F, they calculated that the dissolved gas would spontaneously aggregate to form streams of bubbles wherever crevices and cavities in the glass were greater than 1.4. μm wide. Then, high-speed photographs showed that the bubbles increased in volume as they floated on the surface, capturing and carrying additional dissolved gas in the air above the drink. As the residual gas concentration decreased, the bubbling would eventually cease. Researchers have estimated that there could be between 200,000 and 2 million bubbles released before half a pint of lager is gone. Surprisingly, flaws in a glass will influence beer and champagne differently, with more bubbles forming in beer compared to champagne when larger imperfections are present, the researchers say.
Source of the story:
Material provided by American Chemical Society. Note: Content can be changed for style and length.