The Truth About Good Head

American Spirits

By: Timothy Bleasdale

Posted: 4/17/08

It is white, frothy and sits between you and your favorite amber libation, but what exactly is head and how does it relate to your beer?. Whether you call it foam or by its proper name, this frothy component of a good brew seems to be causing sharp division in the ranks of beer drinks everywhere. With a little prying, the case for or against head can usually be broke down along the lines of how the drinker is imbibing their beer and why they have chosen to drink beer instead of something else. But at the root of this question, though, is what exactly this foamy substance is and why it is in beer in the first place.

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While the most obvious source of head is carbonation, this is definitely not the only cause or else other carbonated beverages like soda and champagne would also develop long-lasting foam. So what's the difference? For this we must look back to the very beginning of beer production. As it turns out, one of the main culprit for this phenomenon is a protein called lipid transfer protein 1 (LTP1) which is found in barley, one of the four main ingredients in beer. By itself, LTP1 and carbon dioxide are not enough to cause the foam. In its natural state, LTP1 is folded into a molecular structure that is not conducive to foam formation. But when brewers set about cooking up beer, they boil together all of the ingredients in beer, aside from the yeast, into a mixture called wort (yeast is later added to the cooled wort to cause fermentation). When the wort is boiled, the heat causes LTP1 to denature or, for the non-nerds, this means the heat causes the protein to change its molecular structure, making it a bit more flexible in terms of bubble formation.

Now let's fast forward through fermentation - you're standing in your kitchen ready to pour out your beer. As long as you've kept the cap on your bottle or refrained from pulling the tab on your can, the carbon dioxide dissolved in your beer has stayed in equilibrium with any bubbles that may have formed (the pressure in the container ensures that gases are reabsorbed into the liquid at the same rate as they pass out). When you pull that tab, you reduce the pressure the beer is under, disrupting this equilibrium allowing for carbon dioxide to more readily leave the solution. This is a simple law of gasses known as Boyle's Law and basically means that if your beer is kept at a constant temperature, the release of pressure will cause the carbon dioxide to expand. When the beer is poured into a glass, the agitation of pouring causes more of the carbon dioxide to be released from solution. As the carbonation begins to be released from the beer it begins to nucleate (this means the carbon dioxide molecule gets together with other carbon dioxide's and forms something like a band, only more bubbly) on small imperfections on the surface of your glass. As these small 'pockets of gas' pass up through the beer, fragments of LTP1 (remember our buddy the protein?) form a filmy structure around the gas, otherwise known as a bubble. Get a bunch of these bubbles forming at once and presto - you get head!

So Is Head A Good Thing?

Head is an essential feature of quality beer. Not only does the correct amount of foam on your brew look pleasing to the eye, but it assures you that the glass is clean and that the beer is properly carbonated. When the foam forms on top of your beer while you pour, it acts as a sort of shield helping more of the carbonation to remain in the brew, an important part of how a beer tastes. Additionally, if the glass your beer is in hasn't been properly cleaned, as in it has any residual food matter or grease, the lipids or fats in these residues will weaken the bubbles in the foam, causing it to collapse. If you're at a bar, this can also tell you about the quality of your bartender. A good bartender will know that he should use sanitizing solution made for use in beer-glassware rather than regular house hold soaps or detergents because these are fat-based and can kill head retention.

So what's up with the anti-headers?

The aversion to head, while mind-boggling to beer enthusiasts, stems from fairly practical reasoning. New beer drinkers, who have never been taught the proper way to pour a beer without overflowing the glass with foam, find the stuff cumbersome. But this is easily overcome. The die-hard adherents to the no-head camp tend to be looking for a way to be able to drink beer quickly. For these characters, the bane of their Friday night is when they go to funnel a Keystone or Coors Light and instead get a tube full of foam. Of course, for the funnelee, this is a precarious place to be given that the object of such a contraption is to quickly down liquid, not foam - which is next to impossible.

Dealing with the bubbles

There are a few techniques you should combine when pouring your favorite brew. Start by simply choosing a wide or broad glass. Although the classic pilsner glass looks pretty snazzy, it was designed to increase head retention, which is why it is so narrow. The broader the glass, the harder it is for the bubbles to stay together and therefore you get less head. When you've picked your glass, hold it at a 45-degree angle as you slowly pour your beer. This slow pouring causes less disruption and so less release of carbon dioxide. The gentle angle of the glass also allows the beer to spread out more along the wall of the glass which also helps to keep things calm.

For the funnelers out there, there really is no quick fix. Once you pour your beer into the device, you've simply got to wait till the foam subsides, which it eventually will. However, if you don't mind risking tarnishing the taste, there are a few tricks you might try. Take the funnel (and only the funnel, not the tubing) and very lightly coat the inside of the funnel with olive oil of even an oil based or buttery cooking spray. If you do this lightly enough, it should minimize the effect of the oil on taste.

But for those looking to make the least effort, simply buy a different kind of beer. Beers brewed with a lot of adjuncts (grains other than barley) such as rice or corn have far less protein in them and so less head. Good examples of this are Budweiser, Coors and Keystone Light. You should also avoid darker beers and wheat beers. Dark beers tend to have significantly more barley in them. As a grain, wheat has far more protein in it than barley. Examples of wheat beers are be Blue Moon or Sam Adam's White Ale. Oh, and when you're in a fix and if you're not terribly squeamish about bodily fluids, rub your index finger on your nose to collect a little grease (natural human lipids!) and stir around the foam (just the foam not the beer). That's one urban legend that happens to be true.

Contact Timothy Bleasdale at

Timothy.Bleasdale@UConn.edu.