Question about racking onto a previous beer’s yeast cake

[Sleepy_D]

I’m going to make a Doppelbock this weekend. To get enough yeast I made an international Amber lager using WLP833 German Bock yeast and I was planning on just racking onto the yeast cake/slurry after kegging the Amber. If I hit an OG of 1.090 for the Doppelbock then I’m going to need about 900 Billion cells for a “high gravity lager” pitch rate. When I plug my amber into a yeast starter calculator treating it as a stepped up starter I get an out 1200 billion cells. Do you think I should just pour the new beer onto the entire yeast cake even though it will be about a third more than I need or should I dump out some of the slurry before racking onto it to get closer to the target pitch rate or should I relax and grab another beer

 

[Dland]

If it is convenient, I'd try to get some of the solids out of there, as some of it is likely trub & cold break, along with dead yeast. Otherwise, it would probably be fine just dump in the new wort.

I do this all the time, and have had great results, though I have the luxury of a conical fermentor with a bottom dump to get out the gummiest of the solids. I drain the solids off, usually around 1/2+ quart, and as soon as it becomes runny, I shut valve and leave the rest in.

If you have a bucket or carboys, then poor slurry off into sanitized container, wash out the stuff that sticks in the bottom, and add back slurry and new wort.

 

[AlexKay]

I'm skeptical you can estimate the number of healthy cells in a yeast cake to better than a factor of two.

I'm also skeptical that an overpitch is even a problem, either ever, or more specifically for homebrewing, or even more specifically when homebrewing for a clean fermentation character.

Putting those together, even if you overpitch by a factor of two, I can't imagine it will do bad things to your beer.

So yeah, go for it.

 

[Miraculix]

I'm skeptical you can estimate the number of healthy cells in a yeast cake to better than a factor of two.

I'm also skeptical that an overpitch is even a problem, either ever, or more specifically for homebrewing, or even more specifically when homebrewing for a clean fermentation character.

Putting those together, even if you overpitch by a factor of two, I can't imagine it will do bad things to your beer.

So yeah, go for it.

This!

 

[Sleepy_D]

I'm skeptical you can estimate the number of healthy cells in a yeast cake to better than a factor of two.

I'm also skeptical that an overpitch is even a problem, either ever, or more specifically for homebrewing, or even more specifically when homebrewing for a clean fermentation character.

Putting those together, even if you overpitch by a factor of two, I can't imagine it will do bad things to your beer.

So yeah, go for it.

This is where I was leaning, I’ll just let it rip

 

[hiphoppotamuss]

I do this all the time for imperial Stouts and they turn out just fine. Just be ready with a blow off tube, because there’s likely going to be an explosion!