On the fence about using yeast slury....

[Panderson1]

I am not too experienced on reusing yeast.

Yesterday, I kegged a hazy IPA (closed transfer) from a fermzilla conical. I left the yeast on the bottom of the empty firmzilla with a 1 inch layer of beer on top (hope that makes sense). No oxygen entered and should be all CO2 inside. Still a little pressure inside the firmzilla too... so the yeast has been sitting 30 hours in an empty fermenter but with no oxygen.

Anyways, i was thinking of using that yeast for a brew i did today (chilling down currently).

Any harm in this? It was Verdant IPA dry yeast originally fermenting the hazy.

 

[DBhomebrew]

Carry on.

 

[Kickass]

I do it as often as possible. Yeast is expensive and this is an easy, safe, and effective alternative to buying new yeast every batch.

I typically split my yeast into two mason jars. Then pitch one jar into my next batch. I’ll do this “doubling” 2 or 3 times

Word of caution: if the previous batch is a bigger beer, your yeast could be a little to worn out. If the previous batch OG is above 1.060 I don’t repitch.

If you go from hoppy to something not hoppy, you could get some carry over flavor you don’t want.

 

[Panderson1]

Carry

I do it as often

Word of caution: if the previous batch is a bigger beer, your yeast could be a little to worn out. If the previous batch OG is above 1.060 I don’t repitch.

If you go from hoppy to something not hoppy, you could get some carry over flavor you don’t want.

Hmmm. So the hazy (previous batch) was 1.070. This one is 1.068...... both IPA tho....

I have some us-04 ready to go. Just wondering the best option

 

[Kickass]

Since it’s a very fresh batch of yeast, I don’t think it’d be quite as big of a deal. Honestly, if me, I’d probably still reuse it.

 

[Panderson1]

Since it’s a very fresh batch of yeast, I don’t think it’d be quite as big of a deal. Honestly, if me, I’d probably still reuse it.

Thanks. I did it.... i feel like i added a lot to this next batch lol....

On top of that it seems like i had $100 worth of yeast that i am dumping lol... see pics. I'm dumping into A bucket of ice. Looks gross!

Crazy!

 

[Kickass]

Yep, I hate dumping yeast when I don’t have to. I dumped some last weekend because I didn’t have time to save it. I’m still thinking about that.

 

[Oleson M.D.]

We harvest and reuse our yeast slurries with every brew. I just dumped over 1 gallon of good Diamond Lager Yeast, only because it was many, many generations old. Maybe 30 brews were made using this yeast.
Figured it was time to start over with a first generation yeast.

Not only do you save $$$, but the quality of the yeast will improve up through the 8th or 9th generation.

 

[hottpeper13]

Didn't have a beer to repitch the Voss I collected so I brought it upstairs into the kitchen for bread baking season. Down the drain sucks.

 

[aceluby]

I keep as much yeast as I can. Only time I'll toss it is if I've already got a bunch of the same yeast in the fridge or there is too much dry hop sludge (which is one reason I stay away from dry hopping these days). I lost count at what generation I am for some Lutra I got 6 months ago, but at one point I had so much of it that I just had to toss out a few batches. I even save the dry yeast pitches and even those have never failed me on repitching.

 

[seatazzz]

++++ to all of the above. Repitching yeast is one of the biggest money-savers for homebrewers. It's also a great way to 'build' bigger yeast starters; for example, say you have a bigger beer planned in the next few batches, like an Imperial Stout or IPA, where your OG is in the high 70s-80s. Brew a smaller OG batch of something simple, like a blonde or session IPA, first; if an IPA, and you plan to dry hop, consider using muslin bags to reduce the amount of hop sludge. Then brew your bigger batch, and either save that yeast slurry in jars, or you can rack directly onto the yeast cake in the fermenter. There will be plenty of fresh healthy yeast for that big batch. Overpitching, in my limited opinion, isn't really a thing unless you're using kveik or a saison yeast. A word of caution, if you're going this route; that yeast will take off FAST and furious, so a blowoff setup is an absolute necessity, unless you enjoy cleaning brown gunk off of everything within 10 feet (or further) of your fermenter.

 

[hottpeper13]

Overpitching is only an issue if you are going to reuse that batch. I will rack onto a 1.040-1.045 APA yeast cake for my 1.110-1.134 RIS and then toss that yeast cake.

 

[redrocker652002]

Please excuse my ignorance, and I have read up a little on this,, but how do you all save your yeast? This seems pretty cool to me and I would like to try it, but being a novice I am unsure if I have the know how to do it. RR

 

[RM-MN]

Please excuse my ignorance, and I have read up a little on this,, but how do you all save your yeast? This seems pretty cool to me and I would like to try it, but being a novice I am unsure if I have the know how to do it. RR

Sanitize 4 small glass jars by putting them into boiling water. Leave a little beer on top of the yeast/trub when you bottle, then just swirl it up and pour it into the sanitized jars, about 1/4 of it into each jar. Put a sanitized lid on the jar, loosely so any excess CO2 can escape, then set them in the refrigerator. It would be a good idea to label each jar as to the variety of yeast saved in them and the date.

 

[McMullan]

It's not just about saving money; repitching fresh yeast is rarely for sale, so we have to prep it ourselves, just like 'real' brewers

@redrocker652002, the best way to save yeast is in FV wort, doing what we want it to do, ferment. Not always practical for every home brewer, but I'd rather adjust my brewing output and schedule to enjoy the benefits of pitching the best yeast possible. Nothing worse, imo, than pitching yeast selected to do the opposite of ferment.

 

[redrocker652002]

Thanks for the info. Seems pretty straight forward. How long will the yeast last in the fridge? Is there any way to tell the yeast is still good before I dump it in my wort? How many of the mason jars of yeast would I need for a 5 gallon batch of let's say an IPA?

 

[McMullan]

The longer they're stored in the fridge the more required, because they get used to being dormant in the fridge, instead of active in an FV full of sweet wort.

I wouldn't worry too much about assumed over pitching.

 

[RM-MN]

Thanks for the info. Seems pretty straight forward. How long will the yeast last in the fridge? Is there any way to tell the yeast is still good before I dump it in my wort? How many of the mason jars of yeast would I need for a 5 gallon batch of let's say an IPA?

Yeast stored properly will keep several months but as mentioned it will lose viability. Used fresh, one of the 4 jars will be plenty.

 

[Miraculix]

Everything older than a few days gets a starter in my kitchen. I've had a month old yeast slurry stored in beer not starting and ruining batches. Won't make this mistake again. I actually don't store yeast anymore. I either directly pitch on the yeast cake of the previous beer directly after bottling, or the wort gets new yeast.

 

[Oleson M.D.]

7 to 14 days is about as long as you want to go for storage. Longer than that the yeast will lose vitality.

We have used slurries that were a couple months old, with good results. But it is not ideal!

 

[Whisky River]

When you guys say 7-14 days for best vitality, I assume you mean after kegging/bottling?
Do you factor in the length of time in the fermenter before packaging?

 

[Miraculix]

No

 

[Oleson M.D.]

When you guys say 7-14 days for best vitality, I assume you mean after kegging/bottling?
Do you factor in the length of time in the fermenter before packaging?

When the beer is racked into the kegs, we then harvest the yeast slurry. It is stored in a gallon glass jug, at 36*F.
There is always some beer on top of the yeast cake.
The beer is decanted, and the yeast cake roused up with lots of oxygen infusion, prior to pitching in the next brew.
There is typically zero lag time, maybe a couple hours. The new ferment will take off like a Redstone Rocket.

 

[McMullan]

Start counting days from when fermentation finishes. This is when yeast cells go dormant and viability + vitality start to decline.

 

[redrocker652002]

All great info, but I brew once every few months as I am the only one who drinks beer in my house. So a 5 gallon batch will last me for about a month and a half to two months. I don't have anyplace to store kegs of beer that is cold enough, so maybe, right now, they saving o yeast may not be ideal. Good stuff though, I enjoy reading the info.

 

[Panderson1]

I just listened to a Podcast w Chris White stating that from the time your beer finishes fermenting and the yeart start to drop, you have about 2 weeks to repitch. Also said avoid contact with O2 at all costs if you're trying to store it.

 

[McMullan]

I just listened to a Podcast w Chris White stating that from the time your beer finishes fermenting and the yeart start to drop, you have about 2 weeks to repitch. Also said avoid contact with O2 at all costs if you're trying to store it.

This is a business motivated compromise engineered to fluff up home brewers. Perhaps ask yourself why commercial customers - professional brewers - are routinely advised by yeast suppliers to repitch within a few days or so? I already know the answer.

 

[Panderson1]

This is a business motivated compromise engineered to fluff up home brewers. Perhaps ask yourself why commercial customers - professional brewers - are routinely advised by yeast suppliers to repitch within a few days or so? I already know the answer.

Can't lie. I thought of this too as i was listening. He did sound very convincing though! Lol

 

[renstyle]

Recently listened to the latest episode #80 of The Bru Lab - Applying the Science: Yeast

@McMullan, I've been reading your consistent, unceasing drumbeat for the common-sense option if you are prepared: Pitching live ACTIVE yeast. This podcast made me understand this POV. I get it now.

My takeaway from the podcast was that standard 1:1 starters with DME give a fresh yeast pitch lots, almost an excess, of resources such that it moved more quickly from the aerobic generation stage to the fermentation/dormant stage.

Using *less* DME than the standard 100g/100mL, more like a 1/3 ratio, gave results where the yeast spent MUCH more time in the generation phase, giving you more fresh yeast cells to pitch if you time it correctly. Made me really re-think the starter build-up-and-chill to decant method.

Saving some slurry in the fridge will keep for several weeks, but will need a starter to build up, and I'd really wanna pitch when fully awakened.

 

[cactusgarrett]

Made me really re-think the starter build-up-and-chill to decant method.

I just listened to the first part of that episode and it's got my mind reeling; not really sure what to think yet. The logic checks out, and I can usually be talked into considering anything with seemingly sound logic, but them referencing the work (from episode 62) that suggests a starter wort of 1.008 is best for growth (with enough nitrogen)? It goes against ALL the starter calculators to date, and I don't know what to think.

And the idea that when they asked themselves "how much nutrient/nitrogen do you use?", they started with 5g in 1-2L, then noted the Wyeast instruction is (for their product) 2.2g in 5gal - that comes out to 0.1g/1L, not 5g. Other resources note that if you use too much of these nutrient products, you can be doing harm by poisoning the yeast with too much nutrients such as Zinc.

 

[McMullan]

Too much of anything is bad for living things generally. Less than 1.010 is supposed to keep yeast cells in an 'aerobic' state, metabolically*. But for most brewers it's practically impossible to maintain such low gravities for optimised yeast growth - it's not simply a case of making a starter @ <1.010. Most brewers are completely oblivious of fundamental biology. Procedures rarely respect yeast as living organisms. Expect some wild claims, especially when unconfirmed hunches are considered to be established facts.

*Ironically, fermentation - despite producing less ATP (biological currency of all living cells) - is less costly overall. It's a relatively simple metabolic network. Respiration's a tad superfluous, for yeast.

 

[cactusgarrett]

So are you suggesting there's merit to this and the practice is a viable alternative to the long-held undertanding?

 

[McMullan]

No, unless you can maintain sugar at <1.010. Because you'd need to do so - maintain a constant low sugar level - over time - to actually get the claimed benefits. Otherwise it's just an idea running on too many assumptions and wishful thinks - just brulosophy fundamentalists talking crap. The recent ideas about 'CO2 pressure' assumed as 'new facts' by said fundamentalists just blew me away, in laughter.

 

[cactusgarrett]

No, unless you can maintain sugar at <1.010.

Sounds like the studies this concept is based on didn't maintain sugar content (ie. keep feeding the system just enough sugar to maintain the target level). I'm not arguing one way or the other, just trying to determine the efficacy of this approach, while trying to temper any biases against the Brulosophy guys and their "hot takes".

Start at 38:00

 

[McMullan]

You can't break the laws of physics. That's the bottom line. Offering the impression you get more cell growth from making starters at 1.008 rather than about 1.040 is what I'd confidently describe as 'guff'. 'Random guff'.

 

[renstyle]

Sounds like the studies this concept is based on didn't maintain sugar content (ie. keep feeding the system just enough sugar to maintain the target level). I'm not arguing one way or the other, just trying to determine the efficacy of this approach, while trying to temper any biases against the Brulosophy guys and their "hot takes".

That's where I am with this as well, efficacy. The science being discussed was interesting.

 

[SeeMont]

Pitching Slurry. I had a slurry of Nottingham, stored in a growler with about 1 inch of beer on top, in the frig for a little over two months. I removed the growler of chilled slurry to let it warm up for use. The test I use is the Smell, bad yeast slurry smells bad. When the slurry is warming, It goes nuts, foams, builds up pressure for loosen the cap, This makes a mess so be ready.
Decided to us this old slurry on an English porter. , I decanted the slurry, and pitched a 1 1/2 cups for 6 gallons. This beer turned out great, Finished at my target FG.
This is the longest I have saved a slurry. I would do this again.

 

[Dog House Brew]

Yesterday was yeast day. I took all of my slurries that I had in the fridge and woke them up. Some were from February, some were from June. Obviously the slurry from June took off within a couple hours. The ones from February took until this morning. I only have two stir plates. The others were pitched into shaken growers. My Conan from February was going nearly as fast as my 021 and 3864 yeasts from June. Conan must be stealthy, I’ve never used it before, but keeping it going.

 

[troxerX]

Guys this is going to hurt but got to cough it out my chest, please don’t get offended — we’ve managed to resuscitate 2,000+ year old yeast from the harshest desertic conditions at the Sphinx and tombs of Tutancamel and brew awesome beer with it, and as of recent, everyone’s raving about Kveik yeast which God knows how many hundreds if not thousands of generations old it is, handled at the worst non-aseptic conditions and here we are worried about 2 month old yeasts and 1.060 wort gravities…

 

[Ninoid]

Sanitize 4 small glass jars by putting them into boiling water. Leave a little beer on top of the yeast/trub when you bottle, then just swirl it up and pour it into the sanitized jars, about 1/4 of it into each jar. Put a sanitized lid on the jar, loosely so any excess CO2 can escape, then set them in the refrigerator. It would be a good idea to label each jar as to the variety of yeast saved in them and the date.

Does the lid have to be loosely fitted?
Can it pull something bad from food that is also stored in the refrigerator?
A year ago, maybe more, I reused yeast from yeast slurry and stored it for up to two weeks in a well-sealed jar in the refrigerator where food for the house is kept. I used it until the 5th generation.