Too insane of extra headspace?

[Cevans95]

I have the opportunity to purchase a 40 gallon stainless steel conical fermenter that is temperature controlled at a ridiculously low price. I usually only brew 10 gallon batches. I understand that majority of the time extra headspace is no big deal with the yeast eating the oxygen and producing CO2 but is this too insane? ( another part of me is telling me to buy it just in case I ever have my dream come true of brewing under an even larger system)

 

[IslandLizard]

I think that large of a headspace is asking for trouble. Infection, oxidation, possibly mold.

If the deal is that good, flip it.

But should one wonder why it's being sold that low...

 

[spittybug]

sanitized beach balls take up a huge volume......

 

[SirSpectre]

Crazy idea....maybe get a sanitary welder to put in a divider. Turn 1 40 gal into 2 20 gallons?

 

[ChelisHubby]

If you see yourself doing 1 barrel batches then this is a heck of a opportunity, but I don't think the extra headspace will be a problem with a small 10 gallon batches.
If I am wrong what is the worst you lose a batch or 2 more opt less 60 dlls and you resale it I would be more worried if I had the space for it!

 

[bigbadgreen]

After you rack into it flow some co2 on top if you want to be extra sure. I would say go for it. Maybe one day you'll be brewing bbl batches.

 

[mongoose33]

I'd think you'd face possible oxygen issues. Yes, normally in fermentation the O2 is being pushed out the airlock, but remember how many cycles of purging a keg is required to get the O2 down to very low levels. Your yeast making CO2 is akin to purging a keg, albeit at a much slower rate.

I've always accepted and hoped that in my 5-gallon batches the CO2 produced by fermentation eventually eliminates most oxygen in the headspace. But I haven't ever tested it, and don't know how I could. All I know is that I don't detect oxidation in my beers, and others with better palates than mine haven't either. So maybe it works.

Now, in a 40-gallon fermenter with 34 gallons of air-filled headspace, how will your tiny 5.5 gallons of fermenting beer do with purging that headspace? My guess is you'll still have a fair amount of O2 in there. Now, will that matter if you rack out from the bottom and leave that CO2/air behind? Doubt it, but would oxidation have already begun before you did that?

Something that would fill up most of the headspace and turn it into deadspace might work--the beachball idea is the right kind of idea for that, don't know if it'd work or not, and cleaning that beachball might be interesting.

Or, perhaps you could pre-purge the headspace with CO2? Get most of the air out of there, and then depend (hope) on fermentation clearing most of the O2?

On the plus side, you probably wouldn't need to concern yourself with a blowoff tube....

 

[doug293cz]

...

I've always accepted and hoped that in my 5-gallon batches the CO2 produced by fermentation eventually eliminates most oxygen in the headspace. But I haven't ever tested it, and don't know how I could. All I know is that I don't detect oxidation in my beers, and others with better palates than mine haven't either. So maybe it works.

Now, in a 40-gallon fermenter with 34 gallons of air-filled headspace, how will your tiny 5.5 gallons of fermenting beer do with purging that headspace? My guess is you'll still have a fair amount of O2 in there. Now, will that matter if you rack out from the bottom and leave that CO2/air behind? Doubt it, but would oxidation have already begun before you did that?

...

This thread comes at an opportune time. I just posted an analysis that fits this situation here. If you read that you will feel much better about the O2 in the headspace of your fermenter.

If I adjust the numbers to fit OP's potential situation (40 L of beer in 160 L vessel, 120 L headspace), then there would be about 878 L or 878,000 cm^3 of CO2 produced by fermenting a 1.050 beer to 1.010. The resultant headspace O2 concentration works out to about 140 ppm. That's enough that a headspace pre-purge might be advisable.

Brew on

 

[day_trippr]

[...]The resultant headspace O2 concentration works out to about 140 ppm. That's enough that a headspace pre-purge might be advisable.

That's a huge number in a bad place.

I think the idea is intrinsically defective, and agree with the person who suggested finding a suitable buyer...

Cheers!

 

[Cevans95]

Thanks for all the replys. I think I may still go through with it just because the deal is so good and try a 12 gallon (in primary) batch purged with a good amount of CO2 just to see what happens. I have 4 taps on my keezer so I can always leave a couple gallons in the keg if it tastes good fresh and try it every couple weeks to see if oxidation gets to it quickly.

 

[bigbadgreen]

As i was thinking about this last night it dawned on me that you could use this to make some sours. Try some open top styles and see what happens. I'm with you, if it's a deal you can't pass up, then do it.

 

[ChelisHubby]

My bet is this works and works well!