Author Topic: Killing off past microbes  (Read 2701 times)

Offline sambates

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Killing off past microbes
« on: January 19, 2015, 07:06:57 PM »
I had a 6-gallon barrel that I used with clean beers 3 times and then aged a cider in it. This cider has potassium sorbate and did not ferment, so now my barrel smells like apple cider vinegar. I aged a lambic in it afterwards and it still smells like apple. How can I clean it out and kill that bacteria to get another sour in there? I was thinking of putting boiling water into it. Thought?
Tap: Brandy Barrel Sour, Brett IPA, Tart Cherry Berliner, Sour Coffee Porter, Witbier, Helles Bock, Helles Bock Braggot, Strawberry "Nebraskambic," Raspberry Flanders
Secondary: OatRye Blonde, Plout Sour, Blueberry Ginger Sour
Primary:Belgian Dark Strong, Scottish Wee Heavy, American Session Wild Ale, Brandy Barrel "Lincolnambic"

Offline hopfenundmalz

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Re: Killing off past microbes
« Reply #1 on: January 19, 2015, 07:34:52 PM »
That is worth a try.

You could also try barokleen or another product like it. Then a suflur stick to kill anything left not too deep in the wood. The sulfur will help keep acetobacter under some control. Brett will go deep in the wood pores, and some say you can't get it out, but you want it for lambics.


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Offline kylekohlmorgen

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Re: Killing off past microbes
« Reply #2 on: January 19, 2015, 09:05:59 PM »
Start with the hot water fill/rinse, then fill the barrel with a solution of cold water, potassium metabisulfite, and citric acid. When you're ready to fill the barrel with beer, empty and rinse thoroughly.

Per Jay Goodwin of The Rare Barrel (and Brewing Network's The Sour Hour), they use a solution of 1 lb potassium metabisulfite and 1/2 lb citric acid per 58 gal.

If you've made three clean turns of that barrel (and the beers are still clean), then you were probably doing things right for the most part. Acetobacter is tough to get rid of, especially in a barrel, but you can limit its activity by limiting oxygen and high temperatures.

Acetobacter needs alcohol and oxygen to make acetic acid (vinegar). Limit oxygen pickup by flushing the barrel with CO2 before racking beer. Fill the barrel to the top until it overflows, then bung and clean the outside surface of the barrel. Limit sampling and popping the bung in general. You might also consider waxing a portion of the barrel to limit oxygen permeability:

Store the barrel in a cool place, preferably between 60F and 70F. Acetobacter activity really picks up above 70F, and brettanomyces/lactic acid bacteria activity drops off below 60F.

Good luck! Please post updates!
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Offline beer_crafter

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Re: Killing off past microbes
« Reply #3 on: March 24, 2015, 03:32:45 PM »
In my experience, boiling (or even 180F) water does kill microbes.

I brewed a sour in a 6 gallon barrel.  I did a 180F soak of the barrel after I was done.  Rinsed it and let it cool and added a cleanly fermented beer to it, with the idea that the microbes in the wood would sour the beer.... after 6 months, the beer was still clean as a whistle!  I was shocked, but it did give me the confidence that I'd be able to control the organisms in the wood to *some* extent (not entirely).