Yeast rinsing - separation question

[nexy_sm]

Hi all guys,

I have yesterday bottled two batches of dry irish stout and rinsed yeast from both fermenters. I separated yeast into several jars and waited for ten minutes. Then I decanted liquid to another containers and discarded sediment. From the second round of jars I discarded liquid and saved sediment after 30 minutes or so. Today, one day after being in the fridge, the collected yeast looks like this:


As you can see there is sediment at the bottom, whitish layer in the middle and top layer. Does this mean that only middle layer contains healthy yeast cells?

Cheers

 

[LLBeanJ]

Well, technically, all of the layers will contain some percentage of healthy yeast cells, but, yeah, that creamy white layer is pretty much all yeast, with only a very small percentage of non-yeast solids.

 

[m00ps]

Yeah the bottom is the stuff you want to ditch.

In the future, i'd suggest harvesting fresh yeast from the starter. Saves you all this trouble of washing and waiting to settle. Plus you get healthy yeast that havent been stressed or exposed to hop oils

 

[Falcon3]

I reuse from my trub all the time- no washing- and have no ill effects- even after doing a DIPA with over a pound of hops for 5g, I reused the yeast and did not have any problem attenuating. Be careful with washing, as the less flocculant yeast have a tendency to be the ones to "survive" washing and float to the top- washing WILL change the character of your yeast after a few generations (all yeast change after generations, but by washing, you are selecting for specific characteristics.)

 

[wapitiscat]

Yeah the bottom is the stuff you want to ditch.

In the future, i'd suggest harvesting fresh yeast from the starter. Saves you all this trouble of washing and waiting to settle. Plus you get healthy yeast that havent been stressed or exposed to hop oils

Thinking about yeast harvesting. I don't usually make starters but this sounds like an extra benefit. So I guess you make your starter then just pitch in the liquid portion and save the sediment to start the new batch. Is that the idea?

Todd

 

[nexy_sm]

The point is that I have already discarded trub and probably some dead cells with the first round of jars. Now I woinder what is in the sediment and what in the middle layer one day after.

 

[LLBeanJ]

Thinking about yeast harvesting. I don't usually make starters but this sounds like an extra benefit. So I guess you make your starter then just pitch in the liquid portion and save the sediment to start the new batch. Is that the idea?

Not quite.

1) Make slightly larger than needed starter.
2) Cold crash a few days to a week or two.
3) Decant most of the starter beer.
4) Swirl up the slurry and pour off a fraction of it to a sanitized container (mason jars work well).
5) Pitch the rest.

 

[LLBeanJ]

The point is that I have already discarded trub and probably some dead cells with the first round of jars. Now I woinder what is in the sediment and what in the middle layer one day after.

That would be lighter trub that did not have a chance to settle in the previous rounds.

 

[nexy_sm]

ok, so another round of separating sediment is needed.

 

[LLBeanJ]

Yes. Or decant the liquid, swirl it all up, and take about a tablespoon of the mixed slurry and make a starter with it. That will give you a lot more fresh cells and only a small amount of trub.

 

[m00ps]

Thinking about yeast harvesting. I don't usually make starters but this sounds like an extra benefit. So I guess you make your starter then just pitch in the liquid portion and save the sediment to start the new batch. Is that the idea?

Todd

I just make make the starter 200ml more (since thats the graduation size on my cylinder), decant like normal, swirl up, and just dump the first bit of the slurry into a sanitized jam jar then the rest into the wort.