Second generation yeast (yeast cake method): Long lag time?

[fendersrule]

Hi gents,

We made a 10.5% stout a month ago. We had the idea that during bottling day that we would simply bottle + brew another stout batch to put on top of the yeast cake, which started from 3 pouches of S-04.

We filled it back up with cool wort (around 60F) about half way, shook the crap out of it, then proceeded to fill it all the way full.

Well, after 3 days of proper fermentation temperature, we are finally getting 1-burp per second.

Is 3 days lag time normal for this method?

 

[Qhrumphf]

A 10.5% beer is gonna be really hard on yeast. The reason your second batch is struggling is the high ABV of the first meant the vitality of the yeast was pretty low.

Pitching on a whole cake is seldom advisable. If it's a really big beer though, sometimes it makes sense (I might brew something like a 3% Bitter to use the whole cake for a massive stout or Barleywine, or a Patersbier cake for a mammoth Quad, or especially a big old Doppelbock). In this case, might actually have saved you. But it's poor standard practice.

 

[Jtvann]

Only thing I can think of is possible stressed yeast from a high alcohol previous brew, or a leak in your system causing it to not bubble.

Check gravity to see what its at.

 

[fendersrule]

Yeah. All good guesses. It was more of an experiment.
I should correct my original post in that the lag time was 2.5 days, not 3 days. Still a bit longer than we would have liked.

It will probably turn out great beer. What is fermenting now is a 10% coffee chocolate breakfast stout.

 

[Robert65]

Yeast should only perform better in subsequent generations; if it shows signs of declining performance, it should be replaced with a new pitch. Even in the first generation, with appropriate pitch rate and oxygenation for the OG, S-04 should reach FG in ~2.5 days from pitching. Obviously it was stressed by the big beer.

 

[RainyDayBrewer]

I guess he tastes the acid that causes the ph to drop. Anyway, tastes sour.

 

[fendersrule]

Wanted to update the thread.

according to the brewing assistant, the beer picked up on the third day.

The fermentation was very mild.

it hit the target gravity of 1.021.

I’m 2/2 so far for pitching right on the spent yeast cake, regardless of OG.

tasted superb. No signs of stress or off taste. Will taste in a few months after carbing.