blowoff missing beer?

[jamest22]

i used a 1" blowoff tube for the first time while fermenting my Bee Cave Bavarian Hefeweizen. I fermented 5 gallons in a 5 gal carboy topped up to the neck. Vigorous fermentation started at apx 68 degrees within 7 hours of pitching the yeast. About 24 hours later I checked the beer. It was still foaming and pushing foam out of the blowout tube. However, I was missing about 1/2 gallon of beer/wort out of my carboy.

My question is, did 1/2 gallons of beer foam up and exit via the blowout tube? Or did pressure build up in the carboy and push liquid beer out?

How much beer from a 5 gal batch is typically lost via a blowout tube on a 5 gallon carboy?

 

[Lou]

i would bet that 1/2 gallon of beer left as foam.

it is not generally advised to ferment 5 gallons of beer in a 5 gallon carboy for precisely this reason.