Oxygen and sours

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Ketchepillar

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I just ordered Roeselare and plan on making a sour soon. I'm just going to pitch that to get it as sour as possible. I've heard various responses on the oxygen debate. At this point, I'm thinking glass over plastic to avoid excess oxygen and it turning to vinegar. I think I'll use an oak dowel but when should I put that in? From the beginning? a few months in? How will the dowel affect the final character of the beer? Any other thoughts on the topic are welcome too.
 
If you want to use a dowel wait until primary fermentation is over, the oak just can’t keep up with the huge volume of CO2 produced.

The three attempts I made to use oak to transfer O2 into sour beers were no better (or different) than my standard method of adding some oak cubes and slapping on an airlock. I just don’t think much oxygen makes it through the oak.

I believe that amount of oxygen that permeates into the large rodenbach tuns has been severely under-estimated (I would guess that oxygen is seeping in at the top where the beer isn’t in direct contact with the wood to keep it swelled). There is just too much acetic character compared to thinner/smaller wine barrel aged brews for me to believe they get so much less oxygen.
 
The top of the beer in a Foudre like they use at rodenbach is protected by the pellicle.
You have to remember that many bugs are able to operate anaerobically. Brettanomyces does not need oxygen and lactobactillus prefers an oxygen free enviorment. I think the only common beer souring microorganism that relies on oxygen is acetobactar, which will turn your flangers red into vinegar.

lambic producers do not top off their barrels for fear of disturbing the pellicle and introducing oxygen.

In short, more oxygen does not always make for a better sour beer.

That said, ive never had rodenbach, so for all i know its a total vinegar bomb, so take what ive said with a grain of salt.
 
Flanders Reds tend to have more vinegar character than any other sour. Which would indicate that they get more oxygen than other sours despite being aged in huge tuns with low surface to volume ratios and thick staves compared to wine barrels.
 
this thread looks somewhat dead so i'll just go ahead and hi-jack it. this is definitely not a classic style and goes way out of the guidelines for a typical sour beer. i figured why not experiment a little, what the hell...

i have a beer in the primary right now which has been there for about 3 weeks. the wort a had a .5 oz fuggle addition at 60 min with a large (4 oz) chinook addition @ 5 minutes from the end of the boil. i pitched a re-used Roselare yeast and the beer has been sitting on the yeast cake since.

now my question: since the beer is in the plastic bucket and the bucket allows more oxygen in than is good for a sour beer, won't the pellicle prevent the O2 from reaching the beer and creating vinegar? the pellicle is created to protect the beer from O2 so how is the plastic bucket necessarily "bad" for storage. for the record all my other brett beers are in carboys!

second question: could the preservative qualities of the hops prevent the vinegar qualities and prevent acetobacteria from taking over?

i have not opened the primary since brew day so i have no idea if a pellicle has formed or anything. i'm gonna check on it soon and see exactly what it looks like. i just want to pick the brains of the HBT lords- any takers?? i don't think there's anything in wild brews about excessive hop usage since it's mostly frowned upon in sour beers.
 
On the subject of O2 and plastic buckets I believe a major concern is the plastic buckets "absorb" oxygen throughout their entire surface areas.
 
now my question: since the beer is in the plastic bucket and the bucket allows more oxygen in than is good for a sour beer, won't the pellicle prevent the O2 from reaching the beer and creating vinegar? the pellicle is created to protect the beer from O2 so how is the plastic bucket necessarily "bad" for storage.
The plastic is oxygen permeable, meaning that O2 can pass directly through the bucket walls and into the beer. This also happens with wood but varies a great deal depending on the size of the barrel and thickness of the staves. Glass and stainless are not oxygen permeable, this is why homebrewers like them because they can control the amount of O2 coming in through the top.
 
On the subject of O2 and plastic buckets I believe a major concern is the plastic buckets "absorb" oxygen throughout their entire surface areas.

Exactly, the oxygen will go straight into the beer, not the headspace. It doesn’t matter anyway as a pellicle will not stop acetobacter (and neither will hops) if there is enough O2 available. If you take a sample and taste a hint of vinegar months down the line just rack it to a carboy until it is ready to bottle.

I don't care for the flavor of old oxidized American hops in any beer, but given time they will completely go away and you should be fine. If you want some of that aroma back just dry hop it right before bottling.
 
Another thing to keep in mind is the temperatures effect on the acetobacter. Vinnie Cilurzo gave a presentation on brewing sour beers at the AHA conferance a couple years ago and he said acetobacter is far more active above 64F. He also said if you get below 60F the other bugs that you want active will slow down too much, so he keeps his barrel room at 62F.
 
I think it was this Sunday Session that had a guest (Chris Colby from BYO) that discussed brewing sour beers in plastic bucket fermenters, and the oxygen permeability issue. Sounded to me like he had a lot of experience in this, and he used buckets exclusively (again, I think). I've never done it (only used BBs and glass), so I can't say one way or another. Just another data point for consideration.

http://thebrewingnetwork.com/shows/The-Sunday-Session/The-Sunday-Session-12-10-06-BYO-Magazine
 
Although I like a little vinegar (alcohol + O2 + Brett/Acetobacter = acetic acid = vinegar) in sour beers, like Rodenbach. I really don't like the ethyl acetate (nail polish) (acetic acid + alcohol + Brett? = Ethyl acetate) aroma that often accompanies it. Rodenbach has somehow gotten around the nail polish, while it's pretty strong in other sours (Deschutes Green Monster, Valley Brew Mutha-Pucka, etc.) Because of this, I really try to avoid O2, and rely on sourness from lactic acid bugs.
 
Although I like a little vinegar (alcohol + O2 + Brett/Acetobacter = acetic acid = vinegar) in sour beers, like Rodenbach. I really don't like the ethyl acetate (nail polish) (acetic acid + alcohol + Brett? = Ethyl acetate) aroma that often accompanies it. Rodenbach has somehow gotten around the nail polish, while it's pretty strong in other sours (Deschutes Green Monster, Valley Brew Mutha-Pucka, etc.) Because of this, I really try to avoid O2, and rely on sourness from lactic acid bugs.

Agreed, but if you want a little acetic edge without the risk you can always blend in some vinegar to taste at bottling.
 
Agreed, but if you want a little acetic edge without the risk you can always blend in some vinegar to taste at bottling.

I totally agree, and I'm glad you said it. I got a hard time last time I mentioned it. It also avoids other negative effects of oxidation: cardboard, muting of malt characteristics, etc. I guess it would be coolest if you could make some homemade malt vinegar and use it.
 
A fact to keep in mind....

The Roselare blend does not have any acetobacter in it. The vinegar notes that can show up from this blend are from the brett. But, it still needs O2 contact to produce the acetic acid. (However, I am pretty sure the barrels at Rodenbach do indeed have acetobacter.)
 
thanks so much for the info. i guess the only thing left to do is rerack to a carboy. i never woulda guessed the plastic itself in the bucket was permeable, i always assumed any O2 was coming in through the lid and into the headspace of the bucket. interesting.

thanks again!
 
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