Question about barrel aging and wild yeast.

I'm not an expert on brew either, I have home brewed quite a bit though. My understanding of the souring process, is base this knowledge on what I have heard, seen, and experience from brewing. So I could also be wrong about this. My educated guess is you brew the wort. If you think you have enough local yeast floating in the air at your brewery you can do an open fermentation. (Cool ship) Eventually when enough wild yeast contact the beer will ferment, making beer. The other method would be to brew the wort and transfer the wort into wooden barrels. While transferring the wort into wooden barrels you put a tremendous amount of wild yeast into the barrels with the wort. Eventually the wild yeast will ferment and make beer. The are three reasons brewers use wooden barrels is to my knowledge for Lambic/wild ales. 1. It gives the beer more flavor. 2. Wild yeast are not like regular yeast. Most yeast is done fermenting in a matter of weeks. Wild yeast ferment at a very slow pace. It takes sometimes years for wild yeast to do its job. (This is why wild ales/Lambics are often more expensive time = money.) 3. Barrels make adequate storage places for those beers and leaves more space in the fermentation tanks for the year around beers and seasonals etc.

 

Spontaneous fermentation happen when the wort is exposed to the night air as it cools in the coolship. The the wort is transferred into barrels, where it ferments. Extended aging is required to let the souring take place, and the ather wild aromas and flavors to develope.

This book is a good source.
http://www.amazon.com/Wild-Brews-Culture-Craftsmanship-Tradition/dp/0937381861

There have been many articles written on these beers, so do some web searches if you wish.

BTW - Lactobacillus and Pediococcus are bacteria. Brett is a wild yeast.

 

For barrel-aged beers that aren't soured, the beer is brewed and fermented "normally" (clean). It then goes into a (hopefully) clean barrel for aging. A new bourbon barrel will likely be clean because the alcoholic strength of the bourbon prevents wild yeast from taking hold. Once a barrel has aged a beer, even a strong one, the chance of infecting the barrel goes up dramatically. I don't think it's possible to keep a barrel clean for round after round of barrel aging, but then again the bourbon character fades quickly as well. I think most breweries that barrel age only use barrels once or twice. Even then, accidents happen as many threads here have attested to.

 

Also once you put wild ale yeast into a wooden barrel. The wild yeast tends to ingrain itself into the wood itself so the barrel will only be good for wild ales/ Lambics forever. As far as regular barrel aged beers go you just put the wort and yeast in there and let the yeast do it's thing. After a while the beer absorbs some of flavor from the wood of the barrel itself. This is why for example a bourbon barrel aged beer has a bourbon flavor. The brewery buys the used barrel from a bourbon distillery and the brewery fills the used barrel with yeast and wort thus making delicious wood aged beer. I hope this answers your questions.

 

Primary fermentations are done in the barrel for Lambics, as the Brett eats the yeast as they break down.

Barrel aged beers such as Flanders reds and bourbon barrel aged beers are fermented then put in the barrel. Yeast autolysis will result in off flavors if left in there beers - meaty, rubbery, soy sauce flavors. Those off flavors are talked about sometimes also in beer theads here.

Once exposed to the bugs and critters, a barrel is inoculated with the organisms and is extremely difficult to sanitize, as those can go deep into the wood pores. Those are reused for sour/wild beers. Most breweries would dispose of a suspect barrel. Wine barrels are disposed of (often sent to breweries doing wild/sours) at the first inkling of Brett.

The best advice Is to read a lot about this and see what experts say on the subject.

 

The line between coolship inoculation and barrel inoculation isn't as solid as it seems. Before there was a wave of scientific research on the subject, many assumed that when lambic wort was pumped to a coolship to cool overnight, the bacteria and yeast that would be doing the fermenting were organisms that came from the air around the brewery and that inoculated the beer in that cooling period.

Now we know that some of that kind of inoculation occurs during cooling, but mostly the organisms that will be doing the lambic fermentation actually come to the beer from the wood in the brewery's architecture and the oak barrels used to age the beer. These areas are where colonies of yeast and bacteria can go on living indefinitely, especially if they are served beer on a continual basis

Exactly how much this matters has led to some controversy between Belgian and American wild brewers. I remember reading a short post by Pierre Tilquin in which he argued with a well-regarded American homebrewer who was attempting to start his own "lambic" program. The homebrewer's plan was to purposely inoculate the oak barrels he would be using for the first batch, and then all subsequent batches would start fermentation from the colony of organisms that would continue living in the wood beyond the store of the first batch. If I remember correctly, Tilquin took issue with the brewer calling this "spontaneous fermentation," as the initial batch was inoculated with lab/home-cultured organisms. Others argued that where the bugs come from initially matters less than how they ferment the beer in future batches, and that the brewer's method was similar enough to the lambic process to call it "spontaneous."

Edit: You'll also notice now that some American brewers who are starting to use coolships store their coolships in their barrel rooms. They know that they will get the best results when the wort is in close proximity to their organism-saturated oak. For example, Jester King's coolship:

 

Sounds like New Glarus Wild Sour Ale

 

There is some good discussion along this line in a portion of this thread from the Homebrewing forum. Some of the posts are from Patrick at The Bruery, which has to carry a lot of professional weight.
http://beeradvocate.com/community/threads/procured-a-whisky-barrel-now-what.102179/