[nateo]

This is new to me so bear with my dumb questions. I'm attempting to do a Berliner weiss by pre-souring the wort before the boil. I made a 4L sour starter of grain and dextrose to grow Lacto, kept hot (110-ish) for 24 hours. pH of starter was 2.9 when I pitched it into the wort.

So the first problem is that I collected a few too many liters of wort, which wouldn't be a big deal except I forgot about the 4L from the starters too. So my total volume was about 8L too much. My target pre-boil gravity was 1.028. Second problem was I forgot to take a gravity reading before I added the starter. So I'm not sure what my OG was. Even with 50% efficiency my wort should have been 1.020.

After 24 hours under a blanket with the carboys wrapped with brew belts, I took a sample. pH was 2.3 and the gravity was 1.016. The airlock was going nuts, so I think some yeast may have survived on the grain too and it was now fermenting.

So, now I'm not sure what to do about the gravity. I can either boil and ferment as-is, or I can try to fix it. I could mash more wort, I could use some DME I have on hand, or I could boil longer. I'm leaning toward one of the first two.

2.3 is lower than I was expecting. What pH should I target pre-ferment? I'm not sure what's typical for Berliner Weiss, but the lowest beer on Raj Apte's chart was 2.8.

Also, are there any concerns with pitching with such a low pH? Should I pitch more yeast than usual?

[nateo]

After digging around a little on the BBBboard it turns out that a lot of lacto varieties are heterofermentative, meaning they make booze and acid, and CO2 in the process. So it's possible, maybe probable, that my gravity drop was just due to the lacto. I'm still a bit concerned about the low pH, but maybe that's actually a normal pH.

[Jimmy K]

Just about any kind of metabolism (yeast, bacteria, fungus, human) is going to eat sugars and produce CO2, I'd say you were successful. I would follow the plan you had originally and see how it comes out. Make changes to your next batch.

[Jimmy K]

And you're not an idiot (because of this anyway)

[nateo]

I know I should RDWHAHB. I haven't done anything like this before, so it's out of my comfort zone. I've been reading about lacto fermentations that never get sour. I wonder if anyone has made a beer with only lacto, and no yeast?

Hopefully the jury is still out on my idiot-status. I would hate to be the subject of a Bill Engvall joke.

[brandon]

My big question is why do you want to boil wort and kill all that great lacto, just to add lacto? I have a few things on my site about Berliners and Lacto that may help.

[nateo]

I was planning on boiling or pastuerizing just to reduce risk of contamination to my other brewing gear, like siphons and such. Is that fear unfounded? Won't a mixed culture like I made have some unpredictable bugs that could lead to bottles bombs down the road? I used grain, not pure cultures. I'll check out that site, and sorry if you've answered those questions on there already.

[brandon]

I was planning on boiling or pastuerizing just to reduce risk of contamination to my other brewing gear, like siphons and such. Is that fear unfounded? Won't a mixed culture like I made have some unpredictable bugs that could lead to bottles bombs down the road? I used grain, not pure cultures. I'll check out that site, and sorry if you've answered those questions on there already.

First off...don't feel bad about asking good questions..

Honestly I'm still confused on what you are trying to accomplish.

You are 24 -48 hours into a sour beer ferment and you are concerned about the gravity? Man you need atleast a couple months before that is a concern. A Berliner should ferment down to 1.005 or below.

[nateo]

First off...don't feel bad about asking good questions..

Honestly I'm still confused on what you are trying to accomplish.

You are 24 -48 hours into a sour beer ferment and you are concerned about the gravity? Man you need atleast a couple months before that is a concern. A Berliner should ferment down to 1.005 or below.

I'm following a sour-worting method I read about on Mike's (The Mad Fermentationist) blog. It's an extension of the sour mash idea. Basically, the beer is soured upfront quickly without yeast, pre-fermentation, rather than slowly post-fermentation. I haven't boiled any of the wort (I know Berliners are traditionally not boiled), or added hops or yeast. In Mike's method, he soured then boiled the wort to make a pseudo-oud bruin.

Right now, I just have the bugs from the grain I grew up in the sour starter. I would guess they're mostly Lacto varieties, and there's probably some amount of yeast and other bugs, but I don't know how much or which ones.

Once I got to my desired level of sourness, I was planning on killing the lacto and other grain bugs and pitching brewer's yeast to finish the ferment. If I had used a pure lacto culture, I wouldn't be worried about it. Maybe my fears are unfounded? Also, any idea where the lacto will finish, pH-wise?