I can not say that I have heard about old wine barrels, although I think somewhere down the line I heard about old bourbon barrels. I know for sure that the Stone Brewery out of northern San Diego county lets some of their beer rest in an oak barrel. Should be interesting.
Hi Michael, fermenting in use wine/spirit barrels is become a lot more popular in the last few years among brewers. It adds another layer of flavor to the beer, can round of some harsh edges on higher abv% beers and, in some cases, is used to house a secondary fermentation with a different yeast/bacteria strain than was used in the primary fermentation.
Being from San Francisco, you have many breweries nearby that use this technique. Firestone Walker ages all their beers in wine barrels. Russian River uses old wine and spirit barrels for many of their Belgian beers. Stone, as stated, uses old spirit barrels, as does Bear Republic. Port Brewing/Lost Abbey uses both spirit and wine barrels. That's what I can think of off the top of my head, but I'm sure there are more.
To try many of these, Toronado in San Francisco would be a good place. I know there are many other good bars/restaurants as well that carry an extensive line of craft beers like this.
Yeah, typically the barrel is steam-cleaned or a chemical is used to be certain there is no residue remaining. Interesting flavour, hard to describe, is imparted. Where is he setting up? I'd like to taste those beers.