I hope people have fun with this.

But, for those who aren't interested in fun, here's a Tl/Dr: What is the fastest way to disperse foam from an overcabonated drink being poured. For example, is it better to pour until the foam crests over the top, maximizing the number of bubbles popping in parallel, or is it better to keep the foam height low, decreasing the number of big bubbles.

As a home brewer, sometimes I end up with a beer that's simply too carbonated. When I pour it, I get a tremendous head (up to 2/3 of the glass). Great. So be it. I'm patient.

Okay, maybe I'm not. Maybe I'm wondering what the best way to pour this beer is. And maybe I have access to a great Q&A site!

So how should one pour a carbonated drink to minimize foaming? The goal is to get the drink into the glass as fast as possible (meaning the foam volume has to be small enough to let me fit the liquid in) without wasting much (a bartender can afford to keep pouring and letting the foam roll off the top, but I can't).

I've seen plenty of sites on how to pour the perfect pour, but I'm looking for what to do with the less-than-perfect pour once I realize I have a too-carbonated drink already!

Variables I'm thinking of:

  • Height of pour (guessing lower is better, but I may be surprised)
  • Glass angle (I've read 45 degrees is ideal, but that's before the glass gets filled with foam...)
  • Speed (If I dribble the drink in slowly, will that make it easier for the foam to dissipate, or should I pour it all in and let it subside)
  • Foam height (do bubbles disappear faster if I let the foam crest just above the top, or is it better to keep the foam as low as possible)

Any other variables which make sense are welcome! And, since this is physics.se, I also want to learn why these tricks work. The physics of beer bubbles baffles me!

  • $\begingroup$ Great, Cort. you post an interesting problem, I post a useable answer, and we get -2 downvote! $\endgroup$ – niels nielsen Sep 4 '18 at 3:32
  • $\begingroup$ @nielsnielsen I was worried it'd happen. Practical physics just isn't as popular as black holes or exotic matter or spherical cows. $\endgroup$ – Cort Ammon Sep 4 '18 at 4:14
  • 2
    $\begingroup$ I thought it was cool for someone with your rep to ask a question that wasn't like, "if the lagrangian density cannot be expressed as a skew-hermitian matrix operator, why does it require 43 1/2 flapjacks to shingle the side of a sh*t house wall?" or something. $\endgroup$ – niels nielsen Sep 4 '18 at 4:20
  • $\begingroup$ Why not just treat every pour as if the beer would be too carbonated? I pretty much start every beer pour at an angle and then adjust it depending on how heady the pour is going. $\endgroup$ – JMac Sep 4 '18 at 11:29
  • $\begingroup$ @JMac Generally that's what I do. But when you put far too much priming sugar in your beer before bottling, even the usual "pour at an angle" approaches can't keep up with the foam. $\endgroup$ – Cort Ammon Sep 4 '18 at 15:05

I have spent hours watching Germans pour their beer in a manner that minimizes the head. Apparently, the key is to pour it as slowly as possible, starting with a very gentle "pour angle" so the beer is slowly running almost horizontally into the glass.

It seems that by disturbing the beer as little as possible, the nucleation of outgassing bubbles is minimized as the pour proceeds.

Also, the importance of NOT agitating the bottle prior to removing the cap cannot be overemphasized!


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