System Issues: Beer Line Location
I have a small scar on my right forearm from my time as a server for a red-roofed pizza chain. I worked there for six years, from high school through college, and have probably eaten ten-thousand pizzas. Fun fact about pan pizzas: the pans are HOT when they come out of the oven, and the old corkboards that servers use to carry them to the table are slippery. Hot pan + slippery corkboard + forearm = hot pan slides from corkboard directly onto my arm. Ouch.
We had a tech call from a pizza place whose beers were pouring straight foam. Everybody have your troubleshooting questions ready? One, two, three, GO! “Do you have gas? Is your gas on? What is the cooler temperature?” Okay, that last question was new; I can’t make it that easy for you.
Pressure and temperature. These variables are the easiest to blame and can be the hardest to determine via phone call. We’ve hammered on pressure for a while, so let’s switch to temperature. Whip out your phone and open the EasyBlend app. Set it to the CO2 content module and adjust these variables: Temperature – 38F, Altitude – 0 ft, Alcohol Content – 5%, Pressure – 24 psi, Blend 70%. You should have a CO2 content of 2.65 v/v which is average for a Domestic Lager. Raise the temperature to 42F. Your CO2 content has changed to… 2.44 v/v. Nice work.
Because of the raised temperature, the CO2 is going to jump out of solution. The molecules are warmer, so they are just bouncing all over the dang place. The draught system is set to dispense at a specific pressure and with the raised temperature, the CO2 won’t stay in solution in the draught line, causing foam and flat beer.
Cooler temperature is a great question but can be tricky. The liquid temperature isn’t always the same as air temperature, even though the thermometer may say 38F. We recommend having a glass of water in the cooler with a thermometer so you can gauge the liquid temperature. This particular tech call had a cooler & liquid temp of 38F, and glycol chiller set to 29F. The beer temp at the glass was around 47F. The glasses weren’t straight out of the dishwasher or frozen, so there had to be a reason why the beer temp spiked so drastically, even with a glycol unit. After some strange follow-up questions, we ruled out old glycol, inaccurate thermometers, and bag regulators. What the heck was left?
Where is the beer line: Is it under the floor or above the ceiling? No way, my dudes. It was behind the pizza oven. I can tell you from personal (arm-scar) experience that pizza ovens are HOT, usually above 500F. “But Kayla, glycol!” Well sure, but you’re going to overwork your glycol chiller trying to cool a bunch of lines that are constantly blasted with hot pizza air during working hours. The solution for this isn’t easy; you can’t just hike up pressure to keep the CO2 in solution since that would overcarbonate the beers in the keg, and you can’t just rely on a glycol chiller to BLAST your beer lines. Moving beer line is an expensive pain in the butt, yet may be the solution for a system like this.