Homegrown Wild Yeast

After I brewed last Monday, I forgot to clean out my graduated cylinder full of wort and a hydrometer… until today when I noticed active fermentation going on in the cylinder out in the backyard. Naturally, I decided to pour that fermenting wort into a sanitized mason jar, where it has continued to ferment. See below. Does anyone have experience with this? I mean, I am not a major sour beer enthusiast, but this seems too good to pass up, provided there are no major risks (a bad 5 gal of beer is not a major risk for me). My thought had been to brew a 10 gal batch of something and split it after primary fermentation into two carboys - dosing one with orval dregs and the other with some of this… to get an idea of what I am working with. I am assuming there is a combination of lacto and brett, but does anyone have a better idea? And should I build up a starter of the stuff, or just pitch the little 4 oz plug od slurry and wort above? The way it is fermenting, it almost reminds me of ordinary sacc…

That’s cool. I just started three experimental wild yeast (hopefully) cultures last night. One with a small piece of plum skin, one with a single grape that was growing on my back fence and one I just left open in the backyard for a couple of hours. There is a sticky thread at homebrewtalk about this that goes on for about 50 pages.

Yours looks good. Keep an eye out for mold. One thing that I have seen mentioned on that other thread is the idea of either heavily hopping a small batch or wort or acidifying the sample to select more for yeasts v other micro-organisms that are less acid tolerant. I did this with my experiments by adding a little lemon juice to each sample. (not very scientific)

Are you still in Davis? or have you moved back down to the east bay yet? the wild yeast in the east bay are world famous for bread making afterall.

From what I have read so far you want to step it up pretty slowly although from your pic it looks like you are getting a lot of yeast already and it does look really clean and beige so perhaps you are right and you caught mainly sacc but you certainly got more than that.

That thread of ‘the other forum’ has a table of times and predominant organisms that can be expected during those times.

I don’t think there is anything dangerous as long as you keep your PH low enough. maybe acidify a starter down to 3.6 or 3.4 and pitch your find into that.

Keep me updated!

I’m in Berkeley now. The beer was VERY heavily-hopped. The activity in there is pretty intense, too - really serious fermenting going on.

Cool! if it’s good maybe I can snag a slug at some point.

how about just doing a 1gal batch?

The logistics of doing a 1 gal batch make it unappealing to me. For one thing, bottle conditioning a sour beer seems too painful and tricky. And I can force carbonate 5 gallons.

so curiously, how does it smell?

Like beer, but a bit more sour - like a brett or lacto-infected beer.

I’d make a 5 gallon (or larger) batch. When finished, rack 1 gallon into a jug and add the ‘starter’. Rack the rest into your bottling bucket or keg and proceed.

This is VERY cool.  You have to let us know how it works out.