2.5 Gallons in 6 Gallon Secondary - Too Much Headspace

I've searched around HBT for information on headspace, but haven't found the answer to my specific questions. I want to start splitting 5 gallon batches in order to experiment with slight, but simultaneous changes to a recipe. I currently have two 6.5 gallon primary tubs and a 6 gallon carboy for secondary. If I bought a 3 gallon carboy, could I split the 5 gallon batch in two and do primary fermentation in the 6.5 gallon buckets and then secondary in the carboys...one in the 6 gallon and 1 in the 3 gallon? Will the 6 gallon with only 2.5 gallons have too much headspace? How does this affect the beer? Is there any problem with doing primary in a less-than-half-full tub (2.5/6.5)? Thanks a lot!

My general rule- At least 50% full for primary and 80% full for secondary.

Too much headspace in a secondary will cause the beer to oxidize. If the beer is done fermenting, it won't create CO2- thus leaving the oxygen in the bucket to settle in to your beer. If you transfer 'young' while a little bit of activity is still going on, you may be able to secondary safely in a larger container- this is because your beer will create a CO2 blanket over the beer and push the oxygen/air out. Of course, you'll get some sediment in your secondary.

If you have a 3 gallon glass carboy, you could rack 3 gallons to that and save a few bucks (and some headspace) and rack the other 2 gallons to a 2 gallon bucket. A cheap and easy way to go.

brewstalker said:

My general rule- At least 50% full for primary and 80% full for secondary.

Too much headspace in a secondary will cause the beer to oxidize. If the beer is done fermenting, it won't create CO2- thus leaving the oxygen in the bucket to settle in to your beer. If you transfer 'young' while a little bit of activity is still going on, you may be able to secondary safely in a larger container- this is because your beer will create a CO2 blanket over the beer and push the oxygen/air out. Of course, you'll get some sediment in your secondary.

If you have a 3 gallon glass carboy, you could rack 3 gallons to that and save a few bucks (and some headspace) and rack the other 2 gallons to a 2 gallon bucket. A cheap and easy way to go.

Click to expand...

Agreed, you dont want that much airspace in your secondary. Gert yourself a 3 gallon glass carboy, that would be perfect!

brewstalker said:

My general rule- At least 50% full for primary and 80% full for secondary.

Too much headspace in a secondary will cause the beer to oxidize. If the beer is done fermenting, it won't create CO2- thus leaving the oxygen in the bucket to settle in to your beer. If you transfer 'young' while a little bit of activity is still going on, you may be able to secondary safely in a larger container- this is because your beer will create a CO2 blanket over the beer and push the oxygen/air out. Of course, you'll get some sediment in your secondary.

If you have a 3 gallon glass carboy, you could rack 3 gallons to that and save a few bucks (and some headspace) and rack the other 2 gallons to a 2 gallon bucket. A cheap and easy way to go.

Click to expand...

Thanks so much for the quick advice! Much appreciated.