Fermenting less than full volume in a conical

[kilroy]

Okay, so I just returned to brewing after 3 years, and a friend of mine gave me a 15 gallon heavy industrial grade plastic conical chemical.. er... holder I suppose you could say, and it looks perfect for fermenting...

Edit: I was told that its quite sturdy and made to not allow ANY kind of gas seepage or induction...

The Question: I only want to brew 5 gallon batches for now.. can I brew 5 gallon batches in a 15 gallon conical? I know that with fermentation, the air would get pushed out by CO2, but would the initial open air volume be a problem? I was thinking about adapting a ball lock to the top to flush the system of any open air, since the brew itself would already be oxygenated?

I need thoughts!

Kilroy, master of the BN cartoons

[DannyW]

Lots of people (and breweries) ferment in open fermenters, so the headspace shouldn't be a big deal.

Or you could just man up, Nancy, and brew 10 or 12 gallons at a time!

[kilroy]

Lots of people (and breweries) ferment in open fermenters, so the headspace shouldn't be a big deal.

Or you could just man up, Nancy, and brew 10 or 12 gallons at a time!

NANCY?!!! Don't make me put you in a cartoon! hehehehe

As an ex microbiologist, I know how important sterile environments are, and I'm just worried that an open air of 10 gallons, or 27ish L of open air would contain possibly around 810 bacterium (its roughly 10/355ml in open air)...

[DannyW]

Almost nothing we do is sterile, sanitary has to be good enough. We rely on overwhelming bacteria with lots of healthy, active yeast. The pH, alcohol, and O2 scavenging by the yeast seems to take care of things pretty well.

Most UK homebrewers ferment open, I think. I've taken to just leaving the lid loose on the buckets here in subtropical Florida and it seems to work fine. Anchor ferments in open shallow stone (I think) fermenters, although in a filtered-air room. many commercial breweries in UK don't even do that and have wide open vats for primary.

I've even heard stories of rats running across the krausen and the beer is fine, but since I have not seen it myself, I'm not sure whether to believe it or not.

[Brancid]

You know, I don't think it's a good idea at all. You should just send the conical to me and I'll let you know how it works out.

[JMUBrew]

You know, I don't think it's a good idea at all. You should just send the conical to me and I'll let you know how it works out.

I like his answer the best!

But, in all seriousness, you should be fine for fermenting in that. During the course of fermentation, the CO2 produced will also help purge the headspace and the Krausen (from what I've been told at least) with open fermentation also helps to form a barrier against bacteria.

[Harleybrews]

If you have a kegging set couldn't you purge the conical with CO2 if you really felt the need to? i don't think you would trouble with it as it though

[Lufah]

Either don't worry about it (what I would do) or purge with CO2.

Travis