American Lambic Project

[dwarven_stout]

You decided to jump on my case for having the audacity to suggest that wood should be an integral part of a process that traditionally uses wood.

Well, I wasn't really trying to jump your case, but to the extent I was it was in an effort to inform. O2 levels in fermenting lambic have far more impact than the circumstances of their arrival. That's why barrels are good (and small barrels can give you vinegar), why the "oak stave" trick is good, and probably even why your process is good (since you initially ferment in plastic).

That said, homebrewing "myths" are something I try to avoid, and I think what you're saying here is a myth. I've heard it before, and I don't think it's correct.

I never said bacteria wouldn’t grow without wood. They will be happier with wood in the fermenter and happier bugs are more likely to give you what you want.

Ok, fair enough. You actually said

The point is that the oak provides a nice comfy home for the bacteria. This is especially helpful for pediococcus which doesn't get started until after saccharomyces has wound down.

so like I said, I'm paraphrasing. Why would pedio need a nice comfy home to be "happy"? Just because it infiltrates wood does not mean that wood is required or even beneficial for its reproduction. Do you have a source that suggests this to actually be true, or is it more of a homebrewing myth?

 

[lowtones84]

I'm not trying to be difficult or take sides here at all, but does whether or not there is scientific proof that bacteria need or even like wood in/as the fermentation vessel matter all that much? To me I would want to use a barrel or oak cubes/staves/spirals or whatever just because it has been done that way for so many years and to me seems part of the character of the brew whether there is detectable "oak character" or not.

And once again not trying to be difficult, just an honest question because I'm not that familiar with this stuff: why can small barrels give you vinegar?

Thanks guys!

 

[emjay]

I'm not trying to be difficult or take sides here at all, but does whether or not there is scientific proof that bacteria need or even like wood in/as the fermentation vessel matter all that much? To me I would want to use a barrel or oak cubes/staves/spirals or whatever just because it has been done that way for so many years and to me seems part of the character of the brew whether there is detectable "oak character" or not.

And once again not trying to be difficult, just an honest question because I'm not that familiar with this stuff: why can small barrels give you vinegar?

Thanks guys!

Smaller barrels can give you vinegar because they allow a lot more oxygen in through the wood, due to a higher surface area to volume ratio.

 

[CadillacAndy]

why can small barrels give you vinegar?

Thanks guys!

I was wondering that as well. I can find places for a few 5-10gal barrels, but trying to fill and store a 60gal barrel isn't going to happen.

 

[CadillacAndy]

Can you seal off portions of the barrel with anything to get you comparable ratios?

 

[Baloo]

There’s a chart in wild brews that details the amount of Oxygen that diffuses through various vessels. A 40L home-brew keg comes in at about the same as a 200L commercial HDPE fermenter and just under 3 times that of a 300L wine barrel. So it’s actually not too bad. I’d be more concerned with sanitation. You’re going to want a used barrel for this, and you’ll want to make sure it doesn’t have an acetobacter infection.

As I mentioned before I’ve been using 12-gallon plastic fermenters, which are way more porous than a small keg and haven’t had a problem with oxidation. Knock on wood. Concern for oxidation is why I’m racking to stainless after the first year for the Geuze project though.


@dwarven_stout I’ll look around for a source but it’s most likely something I picked up in Microbiology back in college.

 

[dwarven_stout]

There’s a chart in wild brews that details the amount of Oxygen that diffuses through various vessels. A 40L home-brew keg comes in at about the same as a 200L commercial HDPE fermenter and just under 3 times that of a 300L wine barrel. So it’s actually not too bad. I’d be more concerned with sanitation. You’re going to want a used barrel for this, and you’ll want to make sure it doesn’t have an acetobacter infection.

Yeah, that's the trick. A barrel left to sit empty can pick up an acetobacter infection relatively quickly. A filled barrel can potentially go vinegary without having acetobacter present (brett *can* make acetic acid but the circumstances aren't all that well understood), but if you have any acetobacter present you need oxygen to produce acetic acid. That happens more in small barrels, as you pointed out.

 

[emjay]

I was fairly certain that Brett needed oxygen for the acetic metabolic pathways as well, no? I'd have to look up my notes and references to be 100% sure, though...

 

[Baloo]

It does. You get acetic acid by replacing two of ethanol's hydrogen molecules with oxygen

 

[spearko520]

i think oldsock's comments in his blog about oxygen levels and funky math are kind of spot on, and should raise a little interest. I have full size barrels now, but have used 5 g ones in the past, and have not had vinegar beer. I do always top any head space whenever i open with an inert gas - nitro, argon, or co2- whatever i have a bottle of- but that really shouldn't protect the surface area of the beer in contact with the wood. I'm not sure what the difference is with wood, but when i make sauerkraut in my oak bucket, it always tastes better than when i use a ceramic crock. Same brine, same fermentation space, same cabbage- i do think there is something in the wood, though i may be unable to scientifically explain what it is. That being said- i'm sure great beer can be made in other ways as well- not everyone uses wood. I think my next vessel may be the stomach of sort of animal...
http://www.themadfermentationist.com/2008/05/with-re-re-release-of-wyeasts-roeselare.html