So Yeah, Dood: Head-Case
One of the holy grails of the intermediate brewer is the achievement of brewing a beer that has good head retention. That is, the beer maintains an appropriate amount of foamy suds throughout the duration of the drink. Despite this, bartenders often spend inordinate amounts of time during their workday spilling off valuable foam into a drain, just to provide the drinker with what is supposedly more bang for the buck. What’s the point of having it at all if it takes up space in the glass that would otherwise be actual beer?
The short answer is that without it — despite getting more liquid — you aren’t getting everything you paid for. Head serves a purpose more important than looking good in advertising. Head acts as a diffuser for the aromas relatively locked and buried beneath the surface tension of the beer. Because we drink beers generally either ice-cold or at cellar temperatures (45-50 degrees), they don’t diffuse molecules into the air as readily as say, red wines or brandies that begin to smell intensely as they are warmed by the heat from our own hands conducted through the glass. That lack of diffusion leads inevitably to a reduction in flavor.
Beer’s aroma arises with the effervescence of the CO2 coming out of solution. You see it rising up from the bottom of the glass or bottle. Head prolongs and intensifies this diffusion, allowing more of the beer molecules to enter our noses. And yes, it looks good in advertising, and ultimately in a glass up close and personal.
Within the brewing process, factors ranging from how much alcohol the yeast produces and how much it settles out of solution, to the amount of unfermented sugars left in the beer all affect whether a beer will generate and retain head. How hoppy the beer is can also be a factor, as hops contain oils that can both help and hinder the process.
A well-poured beer in a clean glass should retain head for a while, leaving a lace pattern down the insides of the glass as the beer is consumed. Typically, with a pint glass, a good pour utilizes the standard “45-degrees-until-half-of-the-glass-is-full-and-then-straight-down-until-full” method. This ought to give the drinker about an inch or inch and a half of head that should slowly decrease until the beer is gone, allowing the drinker the chance to fully smell, taste, and hopefully enjoy the beer.
The cleanliness of the glass also has a huge effect. Any oils that remain on the interior of the glass will cause the bubbles forming the head to burst prematurely, leaving behind a beer with no head and less flavor than you paid for. Particulates in the glass or the beer itself also have an effect. So if you’re drinking a headless beer that has been poured correctly, your glass was probably not very clean.
Just like wines, there are certain types of glasses for certain types of beers. The pint glass is pretty ubiquitous, with the pilsener glass becoming less and less common, but there are also schooners and snifter-like, tulip shaped glasses for use with certain Belgian ales. Of course, there’s also the classic mug, but that’s seen a decline in the United States. Most of these have a mouth that is wide enough to allow for that all-important diffusion. A bottle doesn’t allow for much of that at all, and thus you probably don’t have much — if any — head with a bottle. The same goes for cans. Though admittedly, the portability that bottles and cans give us is a nice thing.
There’s a time and a place for swilling back a few nearly frozen Old Milwaukees. In a Boat with fishing rods seems pretty appropriate and enjoyable to me. But there’s also a time for savoring the flavor of a beer crafted with precision and love, and I contend that that finger and a half of head in your Double IPA will help you unlock that effort.