Brett, Acetic Acid & Extended Aging

[Bearfoot]

Hoping there's a Brett guru out there that can weigh in on this:

I have on hand two 5 Gal Carboys of a 100% Brett Wheatwine I made about 10 months ago. As an experiment I dosed one of the halves with an extra boost of oxygen about 15 hours into fermentation and another mini boost at 24 hours.

As expected, the half with extra oxygen produced a noticeable amount of acetic acid, while the other half remained clean. Now I figure its high time to blend and bottle, so I have found the perfect blend of A and B and am ready to go.

My question though is whether or not the Brett might continue to produce Acetic acid after blending or if I can count on the beer to remain relatively stable as it continues to age in the bottle. The blend I have found is very pleasing, but any more acid and the malt starts to loose its dominance and the rough edges start to show.

I would hate to loose a year's work on a gamble. I'm also hesitant to pasteurize though I doubt the Brett will have much more to say in this fermentation.

Any thoughts would be of great help!

 

[Bearfoot]

So the beer is blended and kegged, with a small portion bottle conditioning with grape juice. Time will tell on my original question, though I suppose If I was really worried I could just drink the stuff as fast as possible.

I'm also noticing that the Acetic acid in fermentor B seems to be waning as time goes on (held on to 2 gallons of each unblended)...is this something that can be expected with Brett, that perhaps it can convert the acid to something less noticeable?

 

[TAK]

Subbed to any feedback you get.

 

[dougdecinces]

I would guess that it depends on if there is any residual oxygen left in your blend. If brett had already consumed all of the oxygen in your oxygenated half, then you shouldn't have anything to worry about. But I don't know how long it takes for oxygen to be consumed in a 100% brett beer. My guess would be that there is no oxygen left, but you should probably wait for a second opinion.

 

[roink]

I'm also noticing that the Acetic acid in fermentor B seems to be waning as time goes on (held on to 2 gallons of each unblended)...is this something that can be expected with Brett, that perhaps it can convert the acid to something less noticeable?

Brett can create Ethylacetate from Acetic Acid and Ethanol.
This would give a solvent like aroma and reduces acidity.

The same thing can happen to the lactic acid. Ethyllactate is created, which has a buttery, creamy, fruity aroma.

 

[CoreyG]

Hey bear foot,

This a little delayed...
I was just curious how you injected oxygen and how much time/technique you used?
Also, how'd the acetic levels turn out in batch B. I had a batch that I exposed to a bit of o2 so I'm curious how your levels of acetic acid turned out because mine is a bit heavy on the vinegar!

Hope to hear back about your experiences