Author Topic: carboy headspace when aging sour beer with brett/bacteria  (Read 3840 times)

Offline sdavis84

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carboy headspace when aging sour beer with brett/bacteria
« on: March 11, 2012, 10:21:19 PM »
I want to age some beer in a carboy with brett/bacteria.  Should I top off the carboy to the top to reduce the headspace/air/oxidation to a minimum?  Or should some headspace be allowed (does the brett/bacteria need a larger top surface area or oxygen to grow and sour the beer)?  If headspace is required, should I purge it with CO2 whenever I open the carboy to sample the beer?  Thanks!

Offline tschmidlin

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Re: carboy headspace when aging sour beer with brett/bacteria
« Reply #1 on: March 11, 2012, 10:29:27 PM »
I wouldn't top it up or purge, a little O2 isn't going to hurt it, but you don't want to oxygenate it either.
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Offline bluesman

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Re: carboy headspace when aging sour beer with brett/bacteria
« Reply #2 on: March 12, 2012, 01:08:40 AM »
Allowing some O2 to in the headspace is good for the bacteria to do it's work. Plus a little head space allows a pellicle to form while the beer ages. I currently have a Flemish Red Ale aging in a six gallon carboy with about 4 inches of headspace. I think a little headspace is okay.
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Offline dimik

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Re: carboy headspace when aging sour beer with brett/bacteria
« Reply #3 on: March 12, 2012, 04:39:52 PM »
As far as I know Brett works better on producing tasty goodness with some oxygen present. So headspace should not be at all detrimental to your beer.
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Offline jakeamo

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Re: carboy headspace when aging sour beer with brett/bacteria
« Reply #4 on: March 14, 2012, 01:09:55 AM »
I would not topoff too much, leave a little space. I have noticed that my sours change their mass/viscosity a little, in the spring the liquid comes close to the bung and in the end off fall and winter the fill line is lower closer to the bottom of where the neck starts. I have no idea what causes this and have wondered for years, since the first one blewoff a little through the airlock. That was after topping off 9mos after the bug pitch. Now i top all my sours right to the bottom of where the neck starts. i would not topoff with water however, because a watery mouthfeel is allready an issue with  the brett and lacto eating all the dextrins. Might be ok in a lambic because the pedio makes a fuller mouthfeel but i would avoid it. I topoff with extra starter wort that i save from last runnings. I actually have found that the brett will make more funk if you feed it dextrinous wort a year after pitching. (See SOLERA). If its funky, i would avoid topping off. Blending is allways an option, i blend most of mine.

Offline bbump22

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Re: carboy headspace when aging sour beer with brett/bacteria
« Reply #5 on: March 17, 2012, 05:01:52 PM »
Allowing some O2 to in the headspace is good for the bacteria to do it's work. Plus a little head space allows a pellicle to form while the beer ages. I currently have a Flemish Red Ale aging in a six gallon carboy with about 4 inches of headspace. I think a little headspace is okay.

Whats Pellicle?  I am brewing my first Flanders Red...Pitched Roeslare into a carboy a few months ago.  Have started seeing what kinda looks like mold in a few patches...is that Pellicle? I hope so. haha. 

mmmm....beer

Offline dimik

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Re: carboy headspace when aging sour beer with brett/bacteria
« Reply #6 on: March 18, 2012, 02:23:55 AM »
That's right. Pellicle is a layer of microorganisms spanning across the liquid medium, beer in this case. I think it's because there is some oxygen available at the surface as opposed to almost a complete lack of it in the rest of the beer, so air loving bugs migrate up there and live slowly with the small amounts they can get. If you open your carboy for a few hours or a day, you'll see the pellicle increase and grow like crazy. Had that happen when someone accidentally unbunged my carboy of a brew that was almost a year old and it stood open for days until I saw that. The pellicle, that sunk completely by then, came back and was the size of a giant pancake... so now it's just sitting there and I'm going to let it ride until it falls out again.
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