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Reusing this yeast cake

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Gustatorian

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Attached is a photo of the yeast harvested from my conical.

What exactly am I looking at. I know the yeast are settled to the bottom, looks like the wort/beer is in the middle, but is that active yeast/krausen on top?

After pulling the yeast from my dump valve, what is the next step for harvesting and reusing it?

IMG_7273.jpg
 

mredge73

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Did you pull this after fermentation or during? I don't know if the bubbles are gas or krausen.

The thin white layer right under the liquid level is what you generally want.
Cool this in the fridge, this will drop all the yeast out of suspension. Pour off the beer and transfer the rest to a mason jar or something similar. It is easier to harvest this layer in a tall skinny glass container.
Fill remaining space in jar with distilled water and put in fridge to cool and allow it to separate again. Carefully separate the trub from the bright white yeast.
Yeast can be kept in the fridge and reused within 2 weeks or so. Any longer and you may need to use a starter.
You can use calculators like the below to help determine how much of the slurry you need to keep for your next brew:
https://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/


Alternatively you can research freezing yeast sample for long term storage. It isn't very difficult and all you need is some freezable containers and food safe glycerin.
Frozen samples typically need step starters, but are ready in under a week.
 
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Gustatorian

Gustatorian

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Did you pull this after fermentation or during? I don't know if the bubbles are gas or krausen.

The thin white layer right under the liquid level is what you generally want.
Cool this in the fridge, this will drop all the yeast out of suspension. Pour off the beer and transfer the rest to a mason jar or something similar. It is easier to harvest this layer in a tall skinny glass container.
Fill remaining space in jar with distilled water and put in fridge to cool and allow it to separate again. Carefully separate the trub from the bright white yeast.
Yeast can be kept in the fridge and reused within 2 weeks or so. Any longer and you may need to use a starter.
You can use calculators like the below to help determine how much of the slurry you need to keep for your next brew:
https://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/


Alternatively you can research freezing yeast sample for long term storage. It isn't very difficult and all you need is some freezable containers and food safe glycerin.
Frozen samples typically need step starters, but are ready in under a week.
On the tail end of fermentation (probably about 2-3 more gravity points left with minimal activity in the bubbler). When is the optimal time to pull yeast from a conical for reuse?
 

Dcpcooks

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On the tail end of fermentation (probably about 2-3 more gravity points left with minimal activity in the bubbler). When is the optimal time to pull yeast from a conical for reuse?

I prefer to wait until after I hit FG and then I cold crash to harvest. If you harvest it while a portion is still in suspension your selecting the most flocculant yeast and you may have problems with that yeast in the future. It could floc before reaching FG or cleaning up after itself.

If it's a super hoppy beer with a tun of dry hops I'll just spend extra time washing the yeast. If it's a high gravity beer I find it easier to save some from starters and grow up new yeast rather than harvesting it since it's dressed from the high gravity.
 

mredge73

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There may be some benefits to dumping trub early, but yeast collected on the bottom while fermentation is still active will not contain your most active yeast.
You will be getting yeast that flocculated early; at this point your best yeast is either still in suspension or in the krausen if it hasn't dropped yet.
 
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Gustatorian

Gustatorian

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I prefer to wait until after I hit FG and then I cold crash to harvest. If you harvest it while a portion is still in suspension your selecting the most flocculant yeast and you may have problems with that yeast in the future. It could floc before reaching FG or cleaning up after itself.

If it's a super hoppy beer with a tun of dry hops I'll just spend extra time washing the yeast. If it's a high gravity beer I find it easier to save some from starters and grow up new yeast rather than harvesting it since it's dressed from the high gravity.
So do you recommend clearing the dump valve of the flocc yeast a day or two before cold-crashing, then harvesting the yeast from the dump valve after the cold-crash?
 

mredge73

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Yes; yeast that have to be crashed down are your rock stars.

For example:
[ame]https://www.youtube.com/watch?v=VHpOtwGM_a0[/ame]
 
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