Primary fermenter headspace

[JamieGalea]

I am planning in making a smaller batch, like half the fermenter will be filled.

What are the effects of having that much of headspace? If any ...

Thanks

 

[palmtrees]

You'll be fine. There shouldn't be much effect at all if your fermenter is sealed well. The yeast will produce more than enough Co2 to displace that volume. Folks who harvest Co2 from their fermentations can get enough from five gallons to purge two or more kegs. So you'll definitely get enough if you're filling the fermenter halfway. It may be a problem to do something like 1 gallon in a five gallon fermenter, but you should have no issue.

 

[Merleti]

Agree with palmtrees. Remember you want o2 in the beginning. If you are skeptical you can slowly introduce co2 in the extra head space. When? Depends on your initial cell count. If done correct refer to palmtrees suggestions.

 

[CascadesBrewer]

I fermented a 3/4 gallon batches of hop samplers in my 3 gal fermenters. It worked fine, though looked odd. I did not open the fermenter until it was time to bottle. My biggest concerns would be if you had to open up the fermenter after fermentation say to dry hop or take a gravity reading.

 

[bkboiler]

Would recommend unless you are absolutely certain of your seal that you complete primary within a couple weeks.
But yes, I do this all the time, fermenting 2.75 gallons in a ~8 gallon bucket. Fully gaskets and grommeted...I just get it into the keg quickly!

 

[JamieGalea]

I fermented a 3/4 gallon batches of hop samplers in my 3 gal fermenters. It worked fine, though looked odd. I did not open the fermenter until it was time to bottle. My biggest concerns would be if you had to open up the fermenter after fermentation say to dry hop or take a gravity reading.

To take gravity i have a tap installed so i never open the fermenter during fermentation