How much head space in fermenters?

[Firebat138]

ok... we would love to buy a 35 gallon plastic conical... But Tank Depot shipping is outrageous. Spray Smarter has 30 gallon tanks... but we WANT 35. The question is do we NEED 35... We plan on doing three 10 gallon batches and filling up the fermenter... Can we do that with the 30? Should we just get a 40 and if we do... Could we put a 10 gallon batch in it... etc..

thanx all

 

[Bensiff]

You wouldn't want to do 30 gallons in a 30 gallon fermenter unless you want to blow off your healthiest yeast and a lot of beer with it. At that scale I couldn't honestly answer other than I know a 6 gallon carboy isn't quite enough for a 5 gallon batch, I prefer a little more space like a 6.5. So, if I were to extrapolate that out, I would say you are looking at around 25-30% headspace so on a 30 gallon batch I would be looking at the 40 gallon size to have plenty of room. As far as doing a smaller batch, yes you will be fine as it will put off plenty of CO2 to evacuate the air and provide a good blanket...I wouldn't do any aging in that situation, but for a few weeks as long as you have a good seal I wouldn't worry.

 

[Firebat138]

Cool.... But we do 5 gal in 6 gal carboys all the time with no problem... I wonder where the 30 gal mark is in these suckers...