I’ve worked on about four draught system installations here in Montana. I am in no way an expert on installations, and even assigning novice would be a misnomer. I’m fairly good with technical calls (to a certain point) and man, can I crimp an Otiker clamp. I’ve had the distinct pleasure of talking with Dan and Taylor whenever I am confused by any variables with installations or tech calls. I’m writing this at the Annual Convention for GAWDA in Washington DC (because more topics require math, and we know how that goes for me.) I was talking with Dan about this topic to make sure I wasn’t, ya know, super wrong with my approach.
While in DC, I got to spend some time with one of my best friends, who was my college roommate, and we went to a Belgian-style pub. They have more than 24 beers on tap with menu showing the serving temperature of the beers - 42-48F, which is a little warm for my liking, but I’ll try anything twice. I tasted some weirdly good sours, hoppy blonde ales, and something I can only compare to Arbor Mist. I couldn’t help but notice the amount of foam POURING from the faucet. After receiving the beers, I noticed they were less carbonated than I usually prefer, and I can only assume it is because of the foamy foamtown pouring.
Recounting my time at this pub with Dan, his interest was peaked due to the commonality of Belgian beers being pretty high in CO2 content, which makes them difficult to pour. I reassured him that I didn’t start grilling the bar stuff about their draught system, and he asked me what I thought I could do to fix it. Temperature and pressure... you know it’s coming. Since they are advertising their beers at a higher temperature, the applied pressure should be higher to keep those CO2 molecules in solution.
“Well sure, Kayla, but what about the foaming at the tap, you think the applied pressure is the only solution?”
Okay, well now I don’t.
“Increase the pressure, what does that do to the system if it’s designed for the lower pressure.”
It increases the flow rate, beer pours too fast. "Then what?" Slow the beer down...?
People much smarter than me already know the answer.
Line restriction! Systems with issues that can be resolved with a simple adjustment of pressure usually benefit from over-restricting the line right before the faucet. With a smaller diameter line to slow the beer down, it won’t hit the tower intake as quickly which can result in a foamy mess.
If you think your system could be helped by some additional over-restriction, call us (Taylor, Emily, & Dan) for all the math help you need!
If you want to talk to me, that’s cool too, but I’d be more likely to get you some great beer recommendations.