Too much headspace?

[Sundy]

I have 53-liter plastic fermentors. I aim for 20 liters of wort for the fermenter. So more than half of the volume of the vessel is headspace. I have fermented a couple of beers this way and I have not had any flavor issues. The fermentation starts pretty quick and is vigorous for a day or so, definitely not two days. I let it sit for two weeks and keg it. So how much headspace is too much? Why? What size vessel should I buy for 20-liter batches of beer?

 

[day_trippr]

It's not great to have that much head space, especially if the fermentor is allowed to "breath". But kept unopened and tight save for a bubbler over that short two weeks from pitch to kegging it might not pose a big problem wrt oxidation.

It's hard to tell from the picture if that vessel is insulated (like a drink cooler) but if it is I'd be more concerned about how warm the beer gets during active fermentation...

Cheers!

 

[Sundy]

It's not insulated but it is in a conditioned space so it probably stays about 75. That is why my next beer I will use kviek.