Berliner Blunder

Couple things I see here..

One, you didn't need to use aged old hops at flame out. You don't really want a ton of bitterness, because it clashes with the sour, but you also aren't needing to worry about the IBU's inhibiting the lacto since you boiled it after you soured. Could have used any hop, just kept the IBU's in the single digits.

The other, is yes, the pH is going to be low. I suspect it's lower than 4.2. I've gotten mine in the 3.5-3.7 range, and the yeast took a while to get going. One vial, probably, maybe..wasn't enough. You'd really want to pitch well into that hostile environment. You could even look to ferment it slightly warmer as well to maybe perk them up. You also might not see any krausen, as the head rentention of the beer will be lack luster anyways due to the lacto.

I'd give it some time. I've seen 1.5-2 weeks for my berliners to completely finish.

 

Since you have a conical maybe you can rouse the yeast up once you raise the temp to 70 or so? If you don't have that fitting on your conical just drop your O2 stone down in the cone and blast it for a bit to move things around and get more O2 in there to build up your count since you aren't expecting the yeast to impart much flavor here.

 

Hey Dude,

If you're worried about the yeast, pull a sample and make another starter. If the gravity of that starter doesn't drop, you're F`ed! Hopefully, it's fine and it will drop. I'd pitch the high-krausen starter on top of everything and hope for the best.

 

I guess worse case scenario you could alway make a smaller batch, ferment with ale yeast then blend?

While we are on the subject of Berliners, and souring with grain.

What is the chance of getting an alcohol producing lacto strain, or wild yeast that ferments out the batch clean?

And if someone.... was to boil a batch that actually had alcohol for 15 minutes, I'm assuming all the alcohol would be driven off?

 

Ethanol and water mix to form an azeotrope. When you boil the mixture, the vapors contain the same ratio as the boiling liquid. Granted, wort will contain substances besides water and ethanol.

 

Speaking personally, I would pitch some rehydrated US-05 at this point, in the hopes of finishing the fermentation. But I don't have any experience with these sour mash or sour wort beers.

 

Not my area of expertise, but Wikipedia suggests that is only the case for a particular ratio of ethanol-to-water:

"If two solvents can form a positive azeotrope, then distillation of any mixture of those constituents will result in the distillate being closer in composition to the azeotrope than the starting mixture. For example, if a 50/50 mixture of ethanol and water is distilled once, the distillate will be 80% ethanol and 20% water, which is closer to the azeotropic mixture than the original. Distilling the 80/20% mixture produces a distillate that is 87% ethanol and 13% water. Further repeated distillations will produce mixtures that are progressively closer to the azeotropic ratio of 95.5/4.5%. No number of distillations, however, will ever result in a distillate that exceeds the azeotropic ratio."

 

I'm no expert, either. Ethanol is more volatile, so the vapor should be richer in ethanol, as I understand it.

Best data I could find says a 15 minute boil allows for 40% retention of alcohol content.

If you had 4%abv in your sour mash pre-boil, it would be less than 2%abv after a 15 minute boil.

 

That may be a reasonable rule of thumb (I don't know), but it would also depend on total volume and on boil vigor, at least.

 

I believe it depends more on surface area than anything else. A narrow, deep vessel will allow for less evaporation than a wide, shallow one.

 

That would be another factor that would affect how much of the total volume boils away in your 15 minute example. But it's impossible to say which factor is the biggest driver without first bounding the allowed ranges for each.

 

It sounds like you should invest in a better pH measuring device than just test strips. Those things are often difficult to use in brewing. Apart from that, did your sour mash smell okay? I've abandoned that technique on favor of sour worting with a Lacto starter. You could also try the new Lactobacillus brevis culture from Wyeast pitched at the same time as your yeast to avoid pH issues with fermentation.