Is there a problem with having too much head space in a fermenter? I’m thinking about putting 9 gallons in a 14g conical. That comes out to about 35% head space. I’ve heard 25% is ideal. I would assue that the head space would quickly fill with C02 when fermentation begins. Ideas???
That shouldn’t bee a problem as you are correct, the headspace will fill with CO2. I know some wheat strains require 33% headspace.
A couple of years ago I found a food grade plastic 20-gallon container on eBay, that originally had olives from Portugal in it. I put a valve near the bottom and now use it for 10-15 gallon batches. There is lots of dead space, but it quickly fills with CO2, and I’ve never had a blow out since I started using it. The biggest problem is it’s a stretch to reach the bottom to wash it, I can just reach it with enough pressure to adequately clean it. I’ve had as much as 16 gallons of lager in it in the cold garage during the winter without any problems.