Anyone ferment in a non-airtight fermenter for two weeks?

Everyone seems to be talking about the whole "skip secondary and just ferment in primary for the full two-three week duration". Are any of you doing this with a non-airtight container such as a converted keg with an ordinary steel pot lid?

I have a Sabco two-tier converted keg brewery, and I usually ferment in my hot liquor tank, which just has a loose-fitting lid. I'm mildly concerned that after two-three weeks enough O2 would permeate the lid to oxidize my beer. I usually just ferment for a week & then rack to corny kegs & chill. Results are always good, but I do have lots of yeast at the bottom.

Thoughts?

Someone smarter than I may chime in, but CO2 is heavier than O2, so oxidation shouldn't be a concern. Breweries in England and Belgium (and probably other countries) use open fermenters without oxidation problems. I have a fermenter with a screw-on lid that isn't airtight and I haven't had any problems yet (knock on wood) and have gone 3-4 weeks in the primary.

I ferment in a bucket with no airlock and a lid laid loosely over top.

I let the last beer sit in the bucket for a month. I have let beers sit in bucket for 3 months.

So, you ferment in the HLT of your BrewMagic?

Well technically NO fermenters are airtight, if they were then probably half our beers would end up on the ceiling. Airlocks are vents or valves, to release EXCESS co2. Many folks just cover their fermenter buckets with a piece of plexiglass letting the co2 push out between where the plexiglass and the bucket meet. Others cover their carboy mouth with tinfoil. Totally ignoring the need for either an airlock OR a bucket cover.

A lot of folks, especially folks with arthritis, barely even put the lid on tight at all, they just lay it on top. again, if co2 is getting out, NOTHING nasty can get in. And that really is all that matters.

Your beer is cushioned by a layer of co2.

So yes, you could ferment and even long primary that way, as long as the lid is heavy enough to not get popped totally off by the venting co2. But also as long as the EXCESS co2 can get out.

open fermentation is not uncommon. A lot of people have reported, that I've read, in other threads, that they realized their fermenter wasn't closed. It almost never is an issue. Not only does the CO2 purge out any O2, but the yeast is so active and happy early on it out competes any other bugs. You should almost never have problems that early on. For longer bulk aging etc, you do want air tight, as this is when bugs can move in and get busy.

I have my stout in a bucket covered in foil in it's third week right now. Sampled it on Monday and it's perfect!

GilaMinumBeer said:

I ferment in a bucket with no airlock and a lid laid loosely over top.

I let the last beer sit in the bucket for a month. I have let beers sit in bucket for 3 months.

So, you ferment in the HLT of your BrewMagic?

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Yeah, though it isn't a BrewMagic system. Just Sabco brew kettles. I like it because I can boil my chiller in my HLT, drop the boiling water thru my chiller, and have a fully sanitized fermenter & chiller without any chemicals. Works for me!

Guess I won't worry about O2, though I think the "layer" of CO2 is a bit of a myth (at least once fermentation is done & there is no positive CO2 pressure). Temperatures go up and down, gases mix, and O2 gets everywhere. If it was really like oil & water, I don't think we'd be able to breath down here on the surface of the earth, no?

thanks all - looking forward to trying long primaries...

dan

MNDan said:

Yeah, though it isn't a BrewMagic system. Just Sabco brew kettles. I like it because I can boil my chiller in my HLT, drop the boiling water thru my chiller, and have a fully sanitized fermenter & chiller without any chemicals. Works for me!

Guess I won't worry about O2, though I think the "layer" of CO2 is a bit of a myth (at least once fermentation is done & there is no positive CO2 pressure). Temperatures go up and down, gases mix, and O2 gets everywhere. If it was really like oil & water, I don't think we'd be able to breath down here on the surface of the earth, no?

thanks all - looking forward to trying long primaries...

dan

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Troo. But if the fermenter is covered then there is no air current to disturb the CO2 blanket even tho it is not refreshed.

After fermentation is done there should be little to no movement or surface turbulence at the surface of the beer. Very, very, little gas exchange will occur at the surface if there is no turbulence, so I wouldn't be too worried about being airtight.

I thought the CO2 and the ambient air would try and reach an equilibrium?

When I use a vigorously fermenting yeast I'll open ferment. I have had no issues, and I use whitbread (a real mofo) quite a bit.