What next

so i captured some nice looking yeast a few weeks ago, and i want to brew a lambic with it. it has been growing in a mason jar for about 3 weeks and reaching the end of its fermentation. -- whats next? should i just brew and pitch?

If I understand Lambic brewing corretly, I wont get any sourness from this, i need some bacteria for sour taste. I am trying to keep this a wild brew, any way to get it sour without buying the bacterial cultures?

Well...

There are lacto bacilli on malted grains.

I suppose you could throw a handfull into the mix.

Man. Brewing a true lambic is a dedicated hardcore brewing gamble, and I respect you for doing it.

I think Papazian has some info in his book about sour mashing.

I don't have any advise on culturing, but that is probably where it's at bacteria wise.

You need Brettanomyces for the yeast, and those are pretty undefined, even commercially, though I would assume that they would be as varied as the saccharomyces that we all buy...

Now that I think about it, I guess I don't have much to contribute to this topic, other than to wish you luck and patience.

I guess if I could suggest anything, it would be to try several different sources, and brew a few different batches. They have to age for a year, or more. The ones that are crap can go, and you can do blending experiments with the rest.

It's hard to say what you have there. You may have lacto/pedio or some other souring bacteria. You may or may not have brett.

You should figure out what you have before you start adding other strains or sour mashing with it. My advice is to make two 0.5-2 gallon batches of a very generic beer, like a blond or a basic wheat beer of 40% wheat and 60% barley. Split your wild culture between both of them. Bottle one along normal brewing time (so 2-4 weeks in the primary). Let them carb and see how you like them. That will give you a decent idea of what kind of flavors are contributed by any saccharomyces or similar yeasts. You will also know if you have any flavor-contributing bacteria. Let the second batch go for 6-9 months. Then also bottle, let it carb and taste it. This is enough time for any pedio or brett to appear and get to work. That will let you know what an aged version (like a lambic) of your wild culture will produce.

You may find you like one and not the other -- giving you a good idea of what to do with your wild culture. You may like both. Either way, if you want to use it in a lambic it will give you an idea of what additions you need to add.

If you consider "lambic" to be a spontaneous, locally cultured beer then what you produce with your culture is a lambic, whether it is tart/sour or not. If you consider "lambic" to be a style of beer with particular flavor components (tart and brett) then you will likely need to make some additions to what you have to arrive at that flavor combination.

I don't think it is much more work to brew a 5 gallon batch than a 2 gallon batch, so I'd just go for it. Since you let the culture ferment out any really nasty bacteria have probably already been killed by the alcohol and low pH. It takes more than 9 months to really learn what sort of character a Lambic is going to have. If it doesn’t get sour enough you can always add some additional microbes or bottle dregs.

I’ve got a similar project going now. Two of the three cultures I captured look a bit moldy, but the third looks/smells alright. I’m planning to step it up once or twice then pitch it into 5 gallons of Lambic wort (aged hops, turbid mash etc&#8230

Good luck

Thanks for the advice. I guess ill go for it.

If you want to check your sour mash before committing to it, create 2 or 3 sour mash "starters" in some food grade buckets. I use leftover LME buckets. Maybe try a couple of different grains form your LHBS.

Add a cup of crushed grains to a cup and a half of hott-ish tapwater. Cover the surface with foil and put a lid on them.

You'll have to pop the lid on them every 12-24 hours to vent the built-up gasses, at which point you can give them a sniff. Or you can drill a 5/16" hole in the lid to fit an airlock. I found after 48 hours the smell really changes from barnyard to citrus. You can taste it, too, just a little drop on the tongue will have a huge flavor. I found that when I pitched my little sour mash into a larger mash it soured with the exact same smell and taste.