Kegerator, balance that flow!
I’m always amazed when I sit at a bar and watch the bartender pour a pint, but have to dump half or more down the drain because its all foam. That doesn’t have to happen, and I make darn sure it doesn’t happen with my kegerators. Its actually really simple to balance the flow of beer, but if you research it you might find complicated gas volume charts, pressure requirements, temperature and changes to pressure and volume and and and …
I’ve got a science background, have taken chemistry, physics (more than I ever wanted to), biology and calculus. I’ve come to the conclusion that having all that information is good but not all that necessary to pouring a decent pint. We are, after all, talking about beer. Not rocket science.
Three things go into a good pour; temperature, serving pressure and tubing resistance. I like my beer cold, usually around 38degF so I can taste the changes as the beer warms through the pint. I’ve served beer from my taps as cool as 32degF and as warm as 45degF. I like my beer carbonated at 10-12psi. No, I don’t consult the charts to tell you how many volumes CO2 are in my beer, I keep my regulator at 10, force carbonate and serve without having to muck with it. I can hear CAMRA screaming right now! 
It comes down to tubing, the most difficult to change, but easy to work around. When I used shanks and could determine what length I wanted I used 5.5ft of 3/16″ ID beverage tubing with a resistance of 2ppf. Huh, I serve at 12psi, have a resistance of 11… look at that, nice pour!
I have a tower or two that has 3.5ft tubing, serve at 10psi, a bit fast out of the tap but again, decent pour. Get the resistance within three units of serving pressure and enjoy. Yup, its that easy.
Those three things balanced will give a decent pour every time. I might have gotten my facts wrong, my reasoning might be so flawed it boggles the mind but it works!
Cheers!
Interesting article. I like my beer super-carbonated — seems to really bring out the hop flavor and makes the end of the pint as good as the start. But after a few days in the keg I start getting a lot of foam - half a pint or so. I make the best of it by just slurping it down and refilling (what’s wrong with a little extra?) — but I’m wondering if I could get the same carbonation with less foam by changing the tubing length or turning down the temperature. What are your thoughts?
July 7th, 2007 at 10:19 pm
Yup! Are you still using the three headed monster? It’ll take a little doing but not impossible to redo the tubing on it. If I recall, it only has three and a half feet of tubing. If you replace it with six feet you will be amazed at the difference. I’m guessing it pours out of the tap pretty fast right now too, right? Messing with the temp will have minimal effect as far as my experience has seen. Lengthen the tube to get a slower flow.
July 7th, 2007 at 11:18 pm
I think we have the same setup but I force carbonate at 10 psi and serve at more like 5-7 psi. I have decided that the key to a good pour is making sure you don’t add too much psi resulting in overcarbonation. I did make this mistake once or twice when I first started using my kegerator last year. Great article, simple and perhaps usefull to others.
October 18th, 2008 at 12:51 am
Thanks for reading Matt!
October 20th, 2008 at 4:49 pm