Sour Ale - Mashing in a wine barrel?

[Zwerg]

A large part of this question is about mashing, and is not specific to lambic/wild brewing, but this still seemed like the best forum for the question.

My friend and I (homebrewers with limited-to-moderate experience, mostly extract and stove-top partial mash) are interested in brewing a very large batch sour beer together with another friend of ours, who is a winemaker. My friend has access to plenty of 49 gallon barrels, and our thought is to brew a sour beer and age it for about a year in a wine barrel (hoping for plenty of brett and other bugs from the barrel to do their work on the beer during that time).

However, my winemaker friend doesn't have brewing experience, and I am trying to figure out how to handle the mash. Here is my current thinking:

• Batch size: ~49 gallons (~100-120 lbs of malt, ~6-10 oz. hops? Detailed recipe to be worked out later)
• Rent two 30- or 40-gallon stock pots, propane burners
• Heat strike water in stock pots
• Mash using a 49 gallon wine barrel as a mash tun
• Sparge using same process, lauter (somehow, process tbd)
• Boil the wort in the two stock pots
• Rack into two barrels for fermentation
• After fermentation, rack into one barrel for aging (one year? two years?)

Obviously this is a high-risk project given the volume and our relative lack of experience, but we want to give it a go anyway.

Question is, is the above plan feasible? My main concerns are:

• Temperature control: My hope is that such a large volume mash will hold temperature well, and we could probably wrap the barrel with additional insulation. Any cause for concern here? Other possible thoughts include heating with an immersion coil/recirculation pumps/etc.
• Improvising a false bottom/lautering: Is this going to be feasible? I think drilling an additional bung in the barrel for lautering is most likely not a problem, but haven't worked out the details here.
• Yeast/lacto/brett: My winemaker friend makes natural wine, which is spontaneously fermented. I am not sure whether he intends to try to do this with the beer, or whether that's feasible - I know lambic works this way, but I'm wondering if we'd be better off pitching a cultivated strain (obviously with a massive starter). I know very little about lambic brewing and will read up on it, but curious to get anyone's thoughts. Setting aside the yeast question, I think his intention is also to rely on the brett (and lacto?) that is naturally present in his oak wine barrels. My question is, would this be enough? Do we need to pitch additional brett/lacto? We will be aging this beer for a long time and to the extent we can get away with it, we would rather not pitch anything.

Sorry for the unorganized/half-baked thoughts, I'm still in the brainstorming stage but would like to benefit from the board's collective wisdom here. Thanks.

 

[Stas StoLat]

I personally don't ferment in the barrel, but age sour beer in an oak and I solara, removing and adding every year or two, or three if I am lazy or get distracted.