Harvesting & Repitching Yeast

[RufusBrewer]

I brewed an Alt using Wyeast 1007. I had a terrific fermentation. Short lag time, strong healthy ferment, reached finished gravity in 5-6 days, tastes great. When I saw how much stuff I had in the bottom of the primary, I transferred to a secondary and harvested what you see in the pictures.

I collected 4 flasks with 450-500 ml each. What you see in pictures is typical for all 4 flasks. I have not harvested yeast before. I have no idea about what I have in the flasks. I boiled with 1 ounce of pellets for a FWH. So I know some of that stuff is pellet. Any way to tell how much is pellet & how much yeast? I see a thin layer of white. Is that all the yeast, to and the rest is trub and hops?

So what can I do with what I got?

To be honest, I am not interested in putting much more effort into this. I have no problem with tossing these flasks and starting next batch with dry yeast, or fresh yeast and a new starter.
Thoughts. Advice. Suggestions. Best Practices.

t

 

[InspectorJon]

https://www.homebrewtalk.com/threads/simple-yeast-storage-procedure-with-photos.579350/post-7518595

 

[McMullan]

Unless you plan to repitch any of it fresh, without the need to make a starter, I'd dump it in the garden for the wildlife to enjoy.

Concentrated slurry has a very limited shelf life. If you want to save some, a tiny amount of very dilute slurry is going to remain more viable for longer in the fridge than a shed load of concentrated slurry. It minimises slurry fractionation/nutrient exclusion and places much less demand on scant resources remaining in the beer. One of the reasons storing in water is a crap idea, despite what's claimed by bloggers.

 

[Miraculix]

Unless you plan to repitch any of it fresh, without the need to make a starter, I'd dump it in the garden for the wildlife to enjoy.

Concentrated slurry has a very limited shelf life. If you want to save some, a tiny amount of very dilute slurry is going to remain more viable for longer in the fridge than a shed load of concentrated slurry. It minimises slurry fractionation/nutrient exclusion and places much less demand on scant resources remaining in the beer. One of the reasons storing in water is a crap idea, despite what's claimed by bloggers.

I 2nd that, learned that the hard way. I had a lot of beers that displayed heavy symptoms of underpitching when I used slurry that was more than a few weeks old. Sometimes it works but often it doesn't, a bit of a gamble. I don't do this any more, I either do a proper starter from slurry, or I just throw it away.

One thing I'm trying though is freezing the slurry. About 70 % of the batch frozen directly as slurry, probably killed half of it, but still the other half should be fine and good to use. Numbers should be high enough as well. A starter wouldn't hurt though...

 

[balrog]

As you have the flasks for making starters, might I humbly suggest the practice of overbuilding a starter by 100b, saving the 100b as if it were a new package of WYeast, and pitching the rest? Many folks do that, 4-8x or more, with careful sanitation regime.

 

[RufusBrewer]

If I wantEd to sum up the last three posts.

Unless you really know what you are doing, the impressive volume of harvested yeast is not all that useful.

I am not interested in studying to become a beer yeast biologist. Nor spend the time to put such knowledge to use. I will continue to purchase fresh yeast for each batch, make a starter and pitch it. I am good with that.

 

[Gus_13]

As you have the flasks for making starters, might I humbly suggest the practice of overbuilding a starter by 100b, saving the 100b as if it were a new package of WYeast, and pitching the rest? Many folks do that, 4-8x or more, with careful sanitation regime.

This is my preferred method without using science. I know it's not perfect but I have been going off slurry amounts and keeping 200ml of each starter after decanting and I've seen really good results around 100ml of solid slurry after it settles. With lager yeast, I keep upwards of 500ml back usually around 400ml and will have around 250ml of good slurry to build the next starter with.

 

[McMullan]

I had a lot of beers that displayed heavy symptoms of underpitching when I used slurry that was more than a few weeks old.

Yes, even when it looks like a respectable repitching rate it's really underpitching due to poor cell viability, after a week or two. Some home brewers don't mind, but I like fermentation to be predictable and finished within days, not weeks with a risk of stalling. If I'm not pitching fresh yeast I'll start over and make them fresh.

 

[Miraculix]

Yes, even when it looks like a respectable repitching rate it's really underpitching due to poor cell viability, after a week or two. Some home brewers don't mind, but I like fermentation to be predictable and finished within days, not weeks with a risk of stalling. If I'm not pitching fresh yeast I'll start over and make them fresh.

Yes, but my favourite starter is still a full batch of a low to medium strength beer though

 

[bwible]

My understanding is the white layer you see on top is yeast. The darker stuff you see under that is waste and trub. There are articles out there that tell you how to do this. I recall one in particular where the guy uses mason jars.

Personally I plan 2, 3 or more beers in a row with the same yeast. After the first beer I brew subsequent beers on the day I plan to rack, bottle, keg, etc the previous beer and then just put the new beer on top of the leftover yeast cake from the previous beer.

 

[Oleson M.D.]

Yeast slurry will keep up to 5 months, if it is clean and stored around 32-33 degrees.
Our daily driver yeast is Diamond Lager. It is very viable after a month of storage. Longer than that, we will make a starter.

 

[Spivey24]

Yes, even when it looks like a respectable repitching rate it's really underpitching due to poor cell viability, after a week or two. Some home brewers don't mind, but I like fermentation to be predictable and finished within days, not weeks with a risk of stalling. If I'm not pitching fresh yeast I'll start over and make them fresh.

This was my experience last month. I repitched a slurry that was only a couple of weeks old and reasonably clean. I figured there had to be a ton of cells in there given the volume. I normally would have built a starter but it was pretty fresh. It ended up taking 3 days for any significant action. The beer actually turned out pretty good, but I don’t like that much lag. I realized I understand nothing about yeast.

 

[Oleson M.D.]

Diamond Lager Yeast has never shown any issues with repitching. In fact, I took a jug of the harvest out of the fridge, sat it on the countertop in the kitchen, and gave it a good shake. It was perhaps 3 weeks old. Next thing I knew, I had yeast climbing out of the container, running across the counter, and flowing down the cabinets onto the floor. Got it cleaned up before my wife got up! Did not make a starter, this was just harvested slurry.

Now I pitch it straight out of the fridge.

 

[Brooothru]

Diamond Lager Yeast has never shown any issues with repitching. In fact, I took a jug of the harvest out of the fridge, sat it on the countertop in the kitchen, and gave it a good shake. It was perhaps 3 weeks old. Next thing I knew, I had yeast climbing out of the container, running across the counter, and flowing down the cabinets onto the floor. Got it cleaned up before my wife got up! Did not make a starter, this was just harvested slurry.

Now I pitch it straight out of the fridge.

Last summer I did six brews in a little over 4 weeks using 6 different yeasts, all from original fresh packs. All were successful fermentations and produced lots of harvested yeasts. Each was harvested and stored identically in Mason jars on the same shelf in the same beer fridge. A few weeks ago after nearly 8 months, I made starters from each sample using identical procedures of ~200 ml slurry into 250 ml 1.020 SG wort, then stepping twice more with 1.040 SG wort. Each yeast reacted a bit differently, some significantly different.

Of the six samples, 5 had what I consider to be successful propagations, with the sixth showing "signs of life", but just barely (no problem, it's a very common yeast, easily replaced).

The most surprising propagation was some A62 Bell's House that overnight left a krausen ring high up in a 1/2 gallon jug with bubble airlock, shaken not stirred, with 1.020 SG wort. It then chewed right through 500 ml of 1.040 SG wort in one day leaving a prodigious amount of fresh yeast and krausen ring in its wake.

The other four 'successful' entrants took longer to finish but ended up with similar results. I haven't yet fermented with any. They're all crashing and waiting patiently for my return to be decanted. When ready to brew, I'll decant the supernatant and make a small vitality starter a day or so ahead of pitching.

Overall, I was quite pleased with the results of reviving 5 samples of yeast that were approaching their one year mark. Never tried pushing it quite that far.