When you go to a bar and order your favorite draft beer do
you ever feel cheated when the bartender leaves that nasty beer foam on top of
your delicious liquid? Well he’s doing his job and even doing you a favor. AB
INBEV educator, master Cicerone, Max Bakker explains why pouring a beer from
draft or even bottle needs to be done a specific way. Beer has a sound to it
just like your favorite pop/soda. Beer in bottles has a large amount of Carbon
Dioxide(CO2) in it. The CO2 needs to be released into the
glass so that the proper aroma and taste is brought out in the beer. The
Carbonation needs to be released because if it doesn’t get released in the
glass it gets released into your stomach. That’s why some people feel
incredibly full after just one beer. Especially if they drank straight out of
the bottle. A beer is not officially considered a beer unless it has a ring of
foam at the top again to preserve the aromas. If you do not release the
carbonation out of the bottle and drink it straight on average per 12 ounce
beer you will have 2.5 bottles of CO2 fill up your stomach.
All of
the carbonation can make you feel bloated and very gassy. The ring of beer foam
effects flavor by specifically bringing out the sweetness of the malt and the
bitterness of the hops. Beer has 4 main ingredients, grain, hops, yeast, and
water. Even Fox News did a piece on beer foam with special guests from Brooklyn Brewing. Kyle talks about the "foam" coming from the malt protiens and the iso-alpha acids that aid in the aromatics and the escape of the carbon dioxide.
According to ZMsceince proper pour has 2 main steps. Step one, tilt the glass at
a 45-degree angle and vigorously pour the beer along the edge of the glass
until the beer is 60% in the glass. For Step two begin to bring the glass
straight up and down with a ring/collar of beer foam that for a standard beer
is around 1.5 inches. Each variation of a beer has different requirements for a proper pour. Taking my Cicerone certification I learned that there is way more to meet the eye than just pouring your classic lager or Pilsner that Americans love so much but when getting into IPAs, Stouts, Porters and even Triples there needs to be a proper presentation and even a correct style of glass to aid in the aroma and creation of beer foam.
The Science
Carbonation is defined as is the process of carbon dioxide naturally dissolving into a
solution of water under pressure. It is usually found through the creation of
soda, tonic water, bottled water, and alcoholic beverages. The chemical formula
for carbonation is H2C03
(Carbonic acid) --> CO2 (carbon dioxide) + H2O (water).
The carbonation unless acted upon stays in the beer because the
gas doesn’t have enough weight to overcome the viscosity. The gas overcomes
this by binding with dust, fiber, a bump in the glass, and in most cases the
air pcokets when pouring the beer.
Ever thought beer was this complicated or thought the bartender didnt like you by giving you so much beer foam? Maybe he's actually looking out for you and cares about how you feel and your appreciation with beer.
This is certainly a unique contribution. Good title. Some interesting sources, but Fox News is certainly general interest source. The chemistry of carbonation is straightforward and your explanation adequate. I am not sure what the chemical structures are about. It looks like some reaction between a phosphorylated sugar and carbon dioxide. Is that relevant to beer? What is required to release dissolved carbon dioxide into bubbles (cavitation) are nucleation sites. That is why we sometimes add boiling stones to solutions which we are trying to bring to a boil.
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