Souring the Wort and then Fermenting?

kinkothecarp · 09-09-2011, 05:17 PM

We've all heard about souring part of the wort and then fermenting - but what about pitching lactobacillus in, say, 24 hours before you pitch the yeast? Will this develop some sourness and maybe shorten the time that it'll need to age? I mean the actual boiled wort, and not some wort that's been soured and reboiled. So, instead of pitching yeast, I'm going to pitch the bugs, then the yeast.

TheBaconator · 09-09-2011, 05:40 PM

The advantage to souring before the boil of course is that you can stop the souring. You don't have to worry about it taking over your yeast and not getting balance. This is fine if you want super sour. Personally I've had better results (with brett not lacto) pitching at the end of fermentation. I'm partial to a more subtle sour. It's a strong flavor so it will be very noticeable regardless. But the best sour beer I ever made was on accident, I brewed and fermented a stout, put it in my oak barrel to age, and after conditioning it had an excellent sour flavor. Didn't want a sour beer of course, but picking up the brett(didn't know it was in the barrel) and the tiny bit of fermentation that occurred during bottle conditioning was just right.

Just my two cents. If you get your pitching qualities right, putting the lacto in first could yield good results too.

Germelli1 · 09-09-2011, 05:42 PM

You can sour the mash. That way you kill the bugs in the boil, but keep the sourness. With lacto, it is going to get VERY sour if you give it a leg up on the yeast

Nateo · 09-09-2011, 05:43 PM

That's a good way to do it, and that's how most people brew Berliner Weisse, and some breweries do sour beers in general.

With a regular sour fermentation, the kind that takes a long time, most of the souring is done by pedio, and it sours slowly post-ferment. If you use lacto pre-ferment, it will sour quickly.

Lacto is inhibited by alcohol (over 6% ABV, IIRC) and hops (over 7 IBU, IIRC). That's why most people do the souring before the boil (for instance, a sour mash) since there wouldn't be hops yet to interfere with the lacto.

If you do the lacto-before-boil method, it only takes a day or two longer than a regular batch of beer.

Here's a thread on something like what you're describing:
http://www.homebrewtalk.com/f127/fast-lacto-brett-153389/

**jtakacs** · 09-09-2011, 06:47 PM

i did one of my BW like that; pitch lacto, then sacc... frankly it hasn't really soured much at all... maybe a little tart - still young tho.

nofootbreak · 09-09-2011, 06:50 PM

Im pretty sure Lacto ferments anaerobically . If you pitch yeast 24 hours later and oxygenate your wort, the lacto will probably stop working for a period, but I would imagine after the oxygen is gone it would start back up. But I would think you wont get much sour from that 24 hours.

Nateo · 09-09-2011, 09:20 PM

I recently did a Berliner Weisse. I made a 4L sour starter, with 1c whole grains and 400g dextrose. I kept it at 100-110 *F for a day, then pitched it into the wort. My gravity dropped from 1.032 to 1.016 in a day, from the Lacto fermentation. PH got down to 2.3.

I pasteurized the wort and pitched the yeast the next day. The beer is pretty darn sour, and really good. FG finished a bit high, I think because yeast doesn't like working in the acidity. The yeast only dropped the gravity down to 1.009.

I think it would be interesting to do an all-Lacto fermentation. Some lacto strains are homofermentative (they only produce acid), but a lot are heterofermentative (they produce acid and ethanol). The Lacto I cultured from the grain was heterofermentative.