Headless Beers No More

by Abhinav – 

A glass of San Miguel

Why do people drink pints of beer out of glasses? Large bottles of beer, wine, or hard liquor are consumed out of glasses for obvious reasons. But why pints? I mean, they come in such pretty bottles! Why pour them into a glass? Why do people drink beers out of a glass? Well, as it turns out, they’ve got a pretty good reason.

So we’re all aware of a lot of terms associated with beer (pint, lager, barley, belly, hops, stout, keg, yeast, dunkel, weisse, ale, brewing, malt, too much, pub, pilsner, wheat, cask, blonde, bottle, crate, barrel, can, six-pack, on tap, draught, alcohol, bitterness, carbonation, pong, craft, fermentation and the list goes on…). However, as dictated by the German Beer Purity Laws or ‘The Reiheitsgebot’ from the year 1516, beer should consist of just 4 components, being barley, hops, water and yeast. Barley provides the source of carbohydrate or starch. Starch, which is basically a polymer of simple sugars like glucose, has to be broken down into these simple sugars for the purpose of brewing beer. This is achieved in three steps. First, the barley is converted into malt barley by moistening it and allowing it to germinate. The malted barley is then heated and ground in the second step, called kilning. The third step is called mashing in which water is added to the ground malt to allow for the starch to be hydrolyzed into sugars by a process called hydrolysis. As stated earlier, starch is basically long chains or polymers of sugar. These chains or polymers are formed by the formation of what is called a glycosidic bond (See chemical compound below). During hydrolysis, water reacts to break these glycosidic bonds to yield smaller simpler sugars like glucose. While the hydrolysis of starch is taking place during the process of mashing, the temperature of the mixture is increased so as to activate the amylase enzymes present in the barley. These enzymes catalyze (mediate and speed up) the hydrolysis of starch into simple sugars. The mixture is then filtered so that the husks and grains are removed and the water soluble portion, called wort is separated.

Glycosidic Bond (Image credit: study.com)

Now that we have the wort, it is brought to a boil and hops are added. Hops contain a number of acids and essential oils which contribute to the flavor of the beer and are extracted from the plant at high temperatures. The hops are then filtered out after the flavors are extracted and the wort (now flavored) is cooled. There’s a lot more involved with flavoring the beer, but that’s not what we’re interested right now. What we are interested in is what happens next – the addition of yeast to the wort to ferment the sugars. Yeasts are single-celled microorganisms that are part of the fungus kingdom and like others of their kind, they metabolize sugars to produce energy and release water and carbon dioxide as byproducts. However, under anaerobic conditions, yeast cannot metabolize sugar, rather it relies on a process called fermentation which converts the sugars into ethanol and carbon dioxide. It is this phenomenon that not only makes beer an alcoholic beverage but also carbonates it and it isn’t a phenomenon that we are unfamiliar with. Another place where yeast is used is in the baking of bread. Again, the carbon dioxide trapped in the gluten is what causes bread to rise while baking.

Now that the beer is carbonated, it is bottled under pressure to hold the carbon dioxide in the beer. It is the release of this pressure that you hear when you open a can or bottle of beer. In the absence of this pressure, the carbon dioxide would gradually escape from the beer and it would eventually become flat, which is usually the case when a bottle is left open for too long. The reason this takes so long is because the undisturbed beer has surface tension which the carbon dioxide has to overcome to escape the beer. In the case of any turbulence like shaking the bottle for example, the carbon dioxide gets the energy to overcome this surface tension and escape the beer rapidly. An example of this is how soda bottles fizz when opened after being shaken. Another form of such turbulence is when beer is poured into a glass, causing the beer to lose carbon dioxide and it is this phenomenon that causes the formation of beer’s signature head which is basically just bubbles of carbon dioxide escaping the beer.

Beers poured with a frothy head.

Beer head is considered important for a number of reasons. For one, it is fundamental to the aesthetic look of beer and secondly, it also allows for the beer to release certain aromas. There is also debate about how much head a glass of beer should have. While some like pouring their beer in a manner that they get a decent amount of frothy foam at the top (See images above), others like to pour their beer with little to no head whatsoever since it detracts from the volume of beer itself (See Image below). The latter might make sense at first; why would you lose out on beer just for some aromas and an aesthetic look? As it turns out, there’s more to it than that. When you pour a beer with no head, it basically means that there hasn’t been enough turbulence so as to cause the carbon dioxide to escape, thereby not forming any head. Which means the carbon dioxide is still trapped inside the beer. This carbon dioxide then escapes at the next instance of turbulence, which, as you may now have assumed, is after you sip it, inside your body. It’s the equivalent of farting inside your stomach. Sorry for the image created, but it’s true. When you pour a beer without any head, the carbon dioxide that would have escaped from the beer in the glass, ends up releasing in your stomach, in turn making you feel full and bloated much faster than you would have, had you poured the beer with some head. The exact same thing happens when you drink straight out of the bottle, which explains why at least some people prefer to drink beer out of a glass. So, the next time you’re cracking open a cold one, if possible, use a glass. If nothing else, you’ll have more space in your stomach for nachos.

Beer poured without a head.