If I get a 3 gallon biab kit, can I use our normal 5 gallon fermentation buckets or is there too much head space in that bucket? Or can we do 2 three gallon kits in a five gallon bucket and go to six estimated 6 gallon line or is there not enough room to do that?
Others will probably have a much more detailed and reasoned answer, but I think you will be fine. Oxidation is a problem while the wort is hot and after fermentation is complete. You want air (actually oxygen) in the cooled wort before you pitch the yeast.
Primary fermentation is an active and vigorous process and a lot of CO2 will be generated creating a purge and blanket of CO2 at the surface. You will want to be careful not to slosh the bucket around after the beer has fermented - that will introduce more oxygen into the beer. Treat it will care and you should be fine.
Yeah, 3 gals. in 5 is fine. I’m not sure how you would fit 6 gals. in a 5 gal. bucket.
Like ScottNU said, the headspace will be filled with CO2.
Actually it is s 6.5 gallon bucket with a normal brew of 5 gallons
Same points apply. You will be fine. And when you go to a big beer with a huge krausen and the full 5 gallons, you will still be fine. Have fun.
I brew 3 gallon batches almost exclusively, and I use my 6.5 gallon buckets and 6 gallon carboy as primaries the vast majority of the time. You’ll be fine. Headspace is only a concern for extended aging in secondary. I use 3-gallon Better Bottles for that.
You may end up with some blowoff if you try to ferment 6 gallons in a 6.5-gallon bucket, especially with something that produces a big krausen (such as a hefeweizen strain).
Thanks as I really want to try the biab all grain oatmeal cookie brown ale, as we have only done basic kits so far.