A few days ago we talked about how to take care of a mini beer keg for it to arrive in perfect condition at the moment of serving it.
Today we will see how to serve a beer in order to get the minimum amount of foam possible.
I have to say that in general, getting the minimum amount of foam is not the correct way to serve any beer, in deed different beers require different methods and glasses for serving it, but beer with too much foam it is a recurring problem in people that buys a beer mini keg for the first time and therefore we need to address it.
I repeat: This is not a guide to throwing a perfect beer with perfect foam. This is a guide to serve a beer with the minimum amount of foam.
These tips works both for domestic and professionals kegs.
Let’s see how to do it:
– Try to ensure that the beer is in perfect condition to be served. To learn how to check out the previous article I wrote about how to take care of a mini keg.
– Tilt the glass 45 degrees and get it as close as possible to the beer tap. The beer should slide over the surface of the glass, the longer the slide the better. So try that the beer starts falling so close to the edge of the glass as possible.
– Know your beer tap. Most domestic beer taps expel a lot of foam if we open it just a little bit or completely, in most cases the best position for expelling little foam is some intermediate position. Try it a little bit and search what is the optimal degree of opening for your beer tap.
These are the tips that you can use when serving beer, but we have one last final trick for getting little foam.
The glass in which the beer is served has large impact on the amount of foam generated. I collect beer glasses and tried them all (or almost) with my beer tap.
Based on my experience I can say that the best beer glasses for generating little foam are those that make the beer slide over a convex surface. That is, the inside surface of the glass form a convex surface.
Examples of glasses with convex surface:
Examples of glasses with concave surface:
While any glass with a convex surface will be good for this purpose the best glass I found is the nonik glass:
The nonik glass is a pint size glass designed with a bulge on its top. According to Wikipedia, it was designed like that to improve customers grip and preventing the glass to break when stacking.
As you can see the beer first slide over a plain surface that quickly turns into an abrupt concave one and then slides over a convex surface before reaching another plain area again. I do not know what the underlying physical reason, but the fact is that when you slide the beer for this combination of surfaces most of the foam generated would disappear.
If an expert physicist in fluid provides an answer to why this happens, I promise to publish it.