We need enough O2 for yeast to reproduce, alcohol production is anaerobic. Therefore as a country wine maker I will routinely put it in glass at 1.020. ,,,, I haven’t done the math on it but our theory is that CO2 is released as yeast respires which makes the must primarily anerobic, surface oxygen doesn’t dissolve fast enough to saturate and reverse the anaerobic tendency.
Wine yeast tend to be fairly low foam producers so it isn’t too messy, yes it is worth while keeping two or three inches head space. Yes if you use other yeast as ale yeast they foam a lot and your airlock gets messed up/ tossed, , No the foam is hydrated so it is easy to clean off a glass carboy.
Wine yeast tend to be fairly low foam producers so it isn’t too messy, yes it is worth while keeping two or three inches head space. Yes if you use other yeast as ale yeast they foam a lot and your airlock gets messed up/ tossed, , No the foam is hydrated so it is easy to clean off a glass carboy.
I know lowering your temp will slow fermentation, but I wouldn’t think you have that much control over the O2 in a typical fermentation vessel, and I’m sure primary fermentation in a carboy would be messy.