2.5 Gallon Batches - Fermenter

Northern Brewer General
1

I am thinking about trying to do some smaller batches. My idea is to do two 2.5 gallon batches at a time to experiment with hops.

So, if I do a 2.5 gal batch, can I still use a 6 - 6.5 gal fermenter? Or, do I really need to go smaller to avoid too much headspace?

Thanks.

2

With primary, it shouldn’t matter as the head space will fill with CO2 during fermentation.

cheers.

3

[quote=“StormyBrew”]With primary, it shouldn’t matter as the head space will fill with CO2 during fermentation.

cheers.[/quote]
+1, I’ve used 5 gallon carboys and 6 gallon buckets for smaller batches.

4

I do three gallon batches in a fiver all the time.

5

Thanks all.

6

I agree, although I would suggest that you rack to a smaller air-tight container when fermentation subsides. This will avoid oxidation. I would transfer a generous amount of the yeast cake so you don’t stall out the last couple of points and the metabolite cleanup stage.

7

Tom, would that really be an issue? Once the really active ferm stops, you’d still have a layer of the heavier CO2 in the primary as there wouldn’t be enough pressure to expell all of it. No?

cheers.

8

Gas doesn’t sit in layers for long. Brownian movement causes it to mix. As long as CO2 is being produced you have positive pressure and saturated liquid and things are safe. After CO2 production tapers off, if the bucket is well-sealed you could be OK for some time. A lot of mine don’t seal that well and in those the head space is going to be replaced by air pretty quickly.

I’ve just been looking at my methods from a standpoint of reducing oxidation. I’ve seen a lot of beer judges ding homebrews for oxidation, and I think some of mine have had this problem. Especially the malty beers. Its not a huge issue but just one of those things that keeps some of my brews from being as good as they can be.

9

[quote=“tom sawyer”]Gas doesn’t sit in layers for long. Brownian movement causes it to mix. As long as CO2 is being produced you have positive pressure and saturated liquid and things are safe. After CO2 production tapers off, if the bucket is well-sealed you could be OK for some time. A lot of mine don’t seal that well and in those the head space is going to be replaced by air pretty quickly.

I’ve just been looking at my methods from a standpoint of reducing oxidation. I’ve seen a lot of beer judges ding homebrews for oxidation, and I think some of mine have had this problem. Especially the malty beers. Its not a huge issue but just one of those things that keeps some of my brews from being as good as they can be.[/quote]

Ahhh, Brownian movement…of course. :wink: I kid…I kid. Great explaination. Thanks.