While I was in university, I got the opportunity to study for a semester in the Netherlands. Of course, studying was about the last thing I did, largely due to the fact that the city I was in had more bars than restaurants. If you’ve ever been to that region of Europe and visited a bar, you probably know that they take their beer seriously there.
The next time you order a beer from Belgium or the Netherlands and it comes in its own glass, look at the side of the glass. You will notice a fill line with a number and cl beside it e.g., 55cl. This is to tell the bartender where the beer should end, and the foam, or head, should begin. In this region the general rule, when it comes to foam, is that it should be two fingers (laid sideways like you are pointing at something) tall.
It was interesting to see the bartenders in the biggest dive bars in the Netherlands take the time to pour your Heineken. They pour it, level it off with a knife and check to see that there is indeed the right amount of foam. Compare this to other countries like the US, Canada or Thailand even where they tend to pour the beer with a minimal amount of foam.
Love or hate the foam however, you can guarantee that there will be some on almost every craft beer you pour into a glass. The question is, what exactly is this foam, and is it a good thing?
What is beer foam?
Often called head, or foam, this is the mostly white bit you get when beer is poured into a glass. It is created due to the bubbles in the beer breaking the surface and, well, foaming. You may have noticed before that when poured correctly, different beers will have different levels of foam. Scientists believe that this is from a compound found in barley that hates water (is hydrophobic).
This compound essentially clings to the nearest thing around it when introduced to water, which in the case of beer is CO2. When you pour a beer, the CO2 rushes to the top in the form of bubbles, with the compound attached. Once at the top of the beer, the compound forms a coating on the bubble to help protect it from the water. This coating is what we call foam.
Interestingly enough, hops also have a compound that hates water. When combined with compounds found in wheat they too float to the top and serve to make the foam more rigid, stable, and clingy. This is why beers with higher amounts of hops tend to have foam that sticks around longer.
Is foam good though?
Every beer foams when poured into a glass, and according to the science behind brewing, the foam will differ based on the beer and its ingredients. When foam is present in beer, you will perceive the taste differently. Beers with a good amount of foam will feel creamier and almost fluffy in the mouth. This foam serves to essentially soften the overall taste of the beer.
Foam also is important to beer because it traps odours at the top of the beer. When we taste the beer, the first thing we are actually doing is breathing the odour in through our noses. It is the scent which then sharpens and enhances the overall taste. Therefore, a beer with head will allow us to better taste the beer.
Is all foam good?
While some foam on the top of your beer will help improve the perceived taste, there are times when we get too much foam. If you’ve ever taken a sip of a beer that’s more foam than beer you’ll likely notice that the taste is simply overpowering and the overall texture is fluffy.
Therefore, you should aim to strike a good balance. Most beers will do well with under two fingers of foam, the key is to try and pour the beer correctly into a clean glass that has been rinsed to remove any soap particles or oils like lipstick or fingerprints.
Wish of the week
Raspberries are just coming into season now in many countries, and believe it or not, they can lend some really interesting flavors to beer. In this case, Mikkeller used raspberries to produce a lambic beer that any fruit beer lover has to try. With a medium amount of carbonation and strong raspberry flavor, it’s a great summer sipper!