Yeast slurry storage/reuse advice

[darlacat]

I know there's a lot of stuff online about this, but am looking for some direct advice on this question:

Does anyone have any advice on techniques for harvesting yeast slurry (not top cropping)?

I've recently tried the yeast rinsing method, although I'm not convinced by the results - and am concerned that the added water, although sterile, increases the risk of infection. In this case, after settling and decanting I ended up with 3 500ml containers with very little yeast at the bottom (1cm or so), and a 1.5 container that is primarily yeast! Some headspace ended up in the latter, and the introduction of additional water has got me worried about potential infection... in the future I'll probably just save the slurry without any rinsing. I can't see the rinsing element adding much apart from increasing the risk of infection? Could I do anything with the slurry I have saved from this batch, or should I dump it?

Any advice on this would be much appreciated! Looking to keep a few liquid strains on hand for a few generations rather than shelling out for a new package each time I want to use one.

NB I don't have a conical fermenter.

 

[strange-steve]

There's not really any special technique to harvesting yeast, when racking the beer off the trub leave a little liquid behind so you can swirl the solids up, let it settle for a couple of minutes then pour the liquid into sanitised containers and stick them in the fridge. If you're storing them for more than a few weeks then best make a starter. That's really it, just be careful with sanitation. And you're probably right about rinsing, plenty of people don't bother and some reckon it does more harm than good.

 

[Galena]

Have you considered overbuilding when you make a starter? That way if you end up with 500mls to pour off into a Kilner Jar, seal and forget until next time, no yeast washing required.

 

[strange-steve]

Have you considered overbuilding when you make a starter? That way if you end up with 500mls to pour off into a Kilner Jar, seal and forget until next time, no yeast washing required.

This is my preferred method of getting multiple uses out of a packet of yeast.

 

[darlacat]

There's not really any special technique to harvesting yeast, when racking the beer off the trub leave a little liquid behind so you can swirl the solids up, let it settle for a couple of minutes then pour the liquid into sanitised containers and stick them in the fridge. If you're storing them for more than a few weeks then best make a starter. That's really it, just be careful with sanitation. And you're probably right about rinsing, plenty of people don't bother and some reckon it does more harm than good.

Obviously this is not based on any analysis of the cells, but when 'rinsing' the yeast it felt like I was actively willing other organisms into mix and allowing it to become infected. I also ended up with inconsistent amounts of yeast in different containers, and felt like I should have just stored the slurry in some of the leftover wort, as you note. Will likely discard what I've saved in this instance...

On another note, I've posted another slurry question here: How much yeast slurry to pitch, directly harvested?

Do you have any advice on how much slurry to pitch directly from one fermented batch to a new batch of wort?

 

[JockyBrewer]

Very approximately 1ml of yeast slurry = 1 billion cells.

Personally I prefer to do a new starter from my crop.

 

[Cwrw666]

Bad advice probably, but on occasion when I've wanted to put a brew on and don't have any yeast I've just sorted out 3 bottles of a previous brew that have a goodly amount of yeast in the bottom, drunk the beer and tipped the dregs into the next brew.
It's worked, but like I say, probably bad advice...

 

[samale]

I have a starter on at the min. I find spray malt nasty stuff. I think in the future I will just do a mini mash with the required grain.
I have no problems reusing part of the previous brews yeast cake.

 

[terrym]

Try these
https://www.thehomebrewforum.co.uk/...amount-of-harvest-yeast-into-next-batch.88343https://www.thehomebrewforum.co.uk/threads/trub-yeast-re-use.85651/

 

[Gerryjo]

Done a lager on Tuesday night from some LME I had WLP840 on hand but decided to use it for an AG. I had a yeast slurry dated October 19 which I literally sniffed and as it was smelling OK I pitched it yesterday so shall check tonight when I get home to see if there is any activity.

 

[Cheyne_brewer]

I harvested some of the yeast cake from my Fermzilla’s collection vessel. No rinsing, it’s sat in the fridge slowly separating from the wort so theres an inch of clear beer now sat above it. When it comes time to use some I’ll just decant this layer off and make a starter to rouse the yeast from its cold slumber.

 

[Gerryjo]

Update : Bad idea and had to repitch dry yeast yesterday which has kicked off already..
Note to self:
Must brew more often or stop collecting yeast slurry.

 

[nixhaz]

Update : Bad idea and had to repitch dry yeast yesterday which has kicked off already..
Note to self:
Must brew more often or stop collecting yeast slurry.

I pitched a lager onto a small amount (200mls, screwed up, thought I had more) of old slurry on Monday and it took until yesterday to kick off. I was panicking so upped the temperature to 15C and that seemed to do the trick. It's going mental now. Not sure whether to go back down to 12 or just leave it at 15 now though.

 

[Gerryjo]

I pitched a lager onto a small amount (200mls, screwed up, thought I had more) of old slurry on Monday and it took until yesterday to kick off. I was panicking so upped the temperature to 15C and that seemed to do the trick. It's going mental now. Not sure whether to go back down to 12 or just leave it at 15 now though.

Drop it back to 12° where its best suited.

 

[Linalmeemow]

Update : Bad idea and had to repitch dry yeast yesterday which has kicked off already..
Note to self:
Must brew more often or stop collecting yeast slurry.

I've repitched slurry that was 6 months old before with no problems, but I'm not sure I'd go as far as 12+ months without at least making a starter first.

 

[Gerryjo]

I've repitched slurry that was 6 months old before with no problems, but I'm not sure I'd go as far as 12+ months without at least making a starter first.

Shall bear that in mind for next time...