I have approximately 15 gallons of a 8.5% doppelbock sitting at 24 degrees in a half bbl sanke style keg. Was hoping that I could just rack the beer out from under the ice but then realized the beer in spear is liable to freeze too. Dang it, I didn’t think this out!
What do you guys think? Is there a formula out there that can predict what temp a beer will partially freeze depending on ABV? Anyone have any experience doing this? I once made one in a plastic bucket with a spigot on the bottom but I was able to monitor the beer visually. I can’t do that here.
Denny, if you found that info, I could use it too. I’m doing an ice pils starting at about 5.5%. At least I learned here about Major Vice’s dilemma and now plan to pull the dip tube from my corny before freezing. I hope to be able to re-insert it through the frozen slush.
The freezing point (°C) of beer = (-0.42 × A) + (0.04 × E) + 0.2, where A is the percent of alcohol content by weight, and E is the original gravity of the wort (°Plato). Therefore, each 1% increase in alcohol content lowers the freezing point by 0.42° C and each increase in gravity of 1° Plato raises it by 0.04°C. Thus, no beer will freeze at -1°C, and products at higher alcohol concentrations (including high-gravity brews prior to dilution) will withstand even lower temperatures.
As a very general rule of thumb, -1°C for every 2% ABV. A little cooler than a pure ethanol solution due to the carbohydrates in solution.
Keith, you’ve probably long since figured this out but my first thought was to freeze it on its side so the ice would be clear of the stem, then turn it upright to rack the beer out.
Okay,… I seem to work out a freezing point of only -0.95°C. Maybe you can check my work.
A=3.9 (Alcohol by weight)
E=12.2°Plato (OG 1.049)
So…(-0.42xA0)+(0.04xE)+0.2= Freezing point in °C
(-0.42x3.9)+(0.04x12.2)+0.2= FP in °C
(-1.64)+(0.49)+0.2= -0.95°C or 30.3°F