Fermenter Sizes

[hoggyafc]

Not strictly a BIAB question but I do BIAB and this is the forum that I often look in so here's my conundrum...

I usually brew in 11/12L batches in 15L fermenters which works great for me. My problem is that I'm using both my 15L fermenters and want to knock up 12L of Hefeweizen. I've got one of those Coopers fermenters designed for 23L (you know the ones with no airlock). Would this be alright to use for a 12L batch?

[McMullan]

You'll be fine. Thicker blanket of CO2 won't hurt. My only concern is, without an air lock this time of year, your yeast will attract fruit flies to an open FV.

[joe1002]

You'll be fine. Thicker blanket of CO2 won't hurt. My only concern is, without an air lock this time of year, your yeast will attract fruit flies to an open FV.

I think it is one of the coopers fv that have a lid but no airlock - like this

[JamesF]

If it is I think you'd probably be fine to crack the lid every couple of days just to release any pressure. Or you could leave it just cracked open slightly all the time and drape something over the top to stop the fruit flies and suchlike.

James

[McMullan]

Jame's strategy is fine. But you'd have to keep an eye on it. Especially during the first day or two, maybe three. I'd drill a hole in the lid and fix a cheap air lock myself.

[JamesF]

I'd drill a hole in the lid and fix a cheap air lock myself.

That's what I did with my FVs when they had "solid" lids too. Or where I was worried about it frothing over (unlikely to be the case in this instance) I fitted a tube to the bung that ran through a hole in the cap into a PET bottle with a little water in the bottom. An air lock by any other name really, but one large enough to contain any "excitement" at the start of a fermentation rather than having it all over the kitchen floor

Now I have the fermentation cabinet I'm not so concerned. I just lay the lid on loosely on top after high krausen just in case I'm a bit clumsy and drop something.

James

[hoggyafc]

Thanks folks. You are all smashingly helpful.

The fermenter is the coopers one that's designed to let CO2 out without the need for an airlock, I was more worried about so much headspace on the top.

[Fil]

go for it the volume of co2 generated from the fermentation is going to be far in excess of the volume of headroom in your bucket so you will end up with a fully blanketed and protected brew, at our scale of brewing the risk is generally brewing in a too small a vessel and having to deal with a kraussen erruption

[Jocky]

I'd just not seal the lid down, just leave it resting on top - it'll do the job just fine.