How To HARVEST and REPITCH Yeast

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Rather than pitching a fresh pouch of yeast into every batch of beer, most professional breweries reuse yeast harvested from prior batches. And that practice is commonly replicated at the homebrew level. But how best to do it, and what are the limitations? Brülosophy contributor Jordan Folks has harvested yeast for reuse over one hundred times and he’s going to show us exactly how he does it. Plus we’re going to look at the results of an exBEERiment to see if blind tasters could tell the difference between a beer brewed with harvested yeast versus one brewed with a packet of fresh yeast.
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[@peterjohann8781]

I always harvest my yeast and re use it. I have some special yeast which I took as a wild yeast from different locations of the planet, isolated and grew it. I use this over and over again.

[@viper29ca]

Used to harvest, but generally only strains that I bought as a liquid. Dry yeast I would just buy a new packet. Now a days, I pressure ferment, closed transfer the beer out of the keg (or don't bother and just drink the beer out of the same keg) and pour new wort in on top of what is left on the bottom. Maybe every 3-4 brews I will pitch a fresh pack. Mostly using Voss and Lutra, so pretty much works for most styles of beer.

[@silveraven1]

What’s your reason for not reusing the dry yeast?

[@viper29ca]

@@silveraven1 Because it's cheap comparatively to liquid. US05 and other Safale, Mangrove Jack, Lalbrew yeast is like $5/pk. Not worth the hassle and work involved saving it. If I don't have another batch I can throw in on top of it, then I just start with a new pack. I will hold the slurry in the keg for a little while, if I know I am going to be brewing again in a couple of weeks, but otherwise I just use fresh packs.

[@TheAlchemistsBrewery]

Now this is an incredibly useful subject!

[@GREEENZO]

As always, great video! I tend to do overbuilt starters most of the time now which is the same concept, just harvesting at a different point in the process. Just checked one of my jars and lo-and-behold, looked like 50mL of slurry which means approximately 100B cells, exactly the amount I overbuilt by!

[@quillibrium-dk6jz]

For Ale yeast, I do a very similar method, except decant the beer on brew day and take note of the volume. Then I let the slurry warm up and top up with distilled water and shake. I let this sit for a few minutes before pitching and then pitch a percentage of the jar (discounting the distilled water). This distilled water step is an attempt to do a mini rinse on the yeast and hopefully let some of the trub/hops/dead yeast settle out and pitch the most viable yeast.

[@chadlorraine2910]

Great video & info! Like a lot of commenters, I’ve done the yeast wash method a number of times. A well known home brewer had said he top crops his yeast for harvesting, and that’s become my preferred method as well. Would look forward to top cropping being discussed in the future. Thanks so much for all your hard work, Martin😎

[@daveshopfenstube]

Great video! I worked in a traditional brewery in Regensburg, Bavaria for a few months and they even repitched their slurry from a Bockbier with a gravity of 1.064 into their Helles with no issues whatsoever. Also they gone through 50 cycles of harvest and repitch before they get a fresh pitch from the lab. On the homebrew level, I had the same expierence like you Jordan and my method is really close to what you are doing. Hope to see you more often in these videos!

[@dunnmeiertv8943]

Hey, Dave hier! 😂 😅 Greetings from Dresden to all of you

[@pancoasts2002]

What about when you are using dry yeast? Could you collect and reuse?

[@PierceRandall-hf7vf]

Yes. It's the same thing once it's rehydrated and fermenting, either in a beer or starter. People on forums used to say not to build a starter with a dry yeast, but I usually do because that's just how I reuse yeast, dry or otherwise.

[@davidmelching5590]

Here's a recipe if you want to brew a beer that tastes like burned tires: First brew an Imperial Stout (11%) and then directly repitch the yeast from this one in a common Pale Ale. Have fun! Don't ask me why I know ;)

[@centtimmy4951]

Suscribed after 3 minutes feel like hes got a lot of things i would not test myself 😂

[@HaywardParkBrewing]

I don't add hops to fermentation and more so I can reuse my yeast . I do a large hop addition at 80 degrees and then whirlpool instead . I notice no difference in my beers . Might be a good experiment for you

[@bobbob-ze9zo]

like #657

[@PierceRandall-hf7vf]

I use the Brulosophy website method, which I might have been doing before I saw it on the website (I don't remember): Make as starter, pour off 300 ml into a mason jar, pitch the rest. Build the next starter with the mason jar which you keep in your fridge. No need to rinse or stress about gravity or weird hops you used in your last batch. I strongly suspect your pitch rate just has to do with the size and viability of your starter and that it's not even worth keeping track of how many cells you start with. I'll note this seems to work fine for multiple generations even with yeast blends. I haven't noticed a major change to, say, Imperial Dry Hop (a blend of Conan and the Sacc Trois strain) across 3-4 generations. I also freeze my yeast in a bank, and I freeze multiple vials at a time to avoid unnecessary generations. I have to use a small starter to build up from a frozen sample before building a bigger starter. Another thing I plan to do in the future with frothy top-croppers (like London Ale III) is overfill my pressure fermenter and use a blow-off tube out to a 2L bottle (also pressurized) to collect krausen, which would be like how breweries top crop.

[@scottyzlive]

I’m hoping to harvest Lallemand Verdant from a NEIPA 1.068OG at day 4 before dry hop then repitch into a DIPA with OG 1.080 I’ll then toss this yeast. Just hoping to utilise the 2 packets for both batches.

[@AlexSpetz]

I've just kegged and dry hopped a 1.071 NEIPA (after 9 days, including a soft crash, before DH) and harvested the Lallemand Verdant from it. I have an absolute ton of yeast slurry and I'm not not sure what do with it...next beer was planned to be a much lighter hazy but I'm having doubts now 🤣 Beglian Tripel IPA perhaps.....

[@Undergroundfrog]

Jordans audio is really good. Better than most small youtubers/podcasters I come across - impressive!

[@FairDrinkumBrewing]

my estimation is it was recorded via zoom, and the editor used a separate audio track for Jordan, so they could edit the audio with EQ etc how they needed

[@patrickglaser1560]

Needs a bark filter and deesser

[@foxcubbrewing7100]

From my perspective, re-using yeast is a must to save costs, especially if you are brewing at a large scale. But Viability will utilimitly reduce over generations. A common practice to consider would be a Blue Methalyne stain test, which tests the yeasts ability to remove the blue colour of which is checked under a microscope. From this you can accuratly calculate the Billions of Viable yeast within a small sample, and calculate your pitching rate accordingly. Once the yeast viability drops to an unacceptable 90% (target is 95%) then its time maybe start over. Again though great video 🙌

[@WyattCraneum]

I have been using 1-liter club soda bottles for storage. When I'm done with the soda (never drink from it) I just spray some sanitizer in there and put away until i'm ready to put some slurry in it. They work really well and virtually no worry of bottle bombs.

[@jameshoelscher5971]

I have been collecting from the secondary glass carboys for reuse. After a 10th generation brew wasn’t quite right, I have limited reuse to 5 gens also. All ales from SafeAle 05, 10 gallon all grain, pale ales, porters, ryes. 5 days in the primary at 65 F, 7 days in the secondary at 65 F, cold crash 7 - 10 days at 42 F. Keg, force carb to 14 psi … delicious!

[@RiggerBrew]

I have done the yeast cake bit before to 3 generations. Using a Conical fermenter I did drop the trub from each batch. Started with a Cream Ale, then a Nut Brown, and the last was a Porter. They all were great and the last two fermented more vigorously.

[@silveraven1]

So I just use the calculator. So I’m assuming that it’s approximately 100 mil per 5 gallons on a 5% ABV beer? Also, how long would it be viable, that has been properly stored in a refrigerator?

[@Dazbot80]

G'Day from Australia! Can dry yeast be harvested and re-used as successfully multiple times?

[@dslezak17]

So, what to do with slurry from dry-hopped beer? Dont use it? Because i dont understand the clue.

[@19dleeg66]

Wow, awesome info! Did a dubbel, then a tripel (currently fermenting) with the same yeast. After seeing this, I'm going for the quad when the tripel is done. Keep up the good work 🤛

[@bobbob-ze9zo]

Next please try making your own hops shots and using those only for a brew.

[@krisj451]

I would like to know where to get those mason jar lids! They are perfect!

[@JoeWatts1]

Great info here for sure, I always wondered if you could figure out the rough cell count based off the harvested yeast measurement. Thank you! Also, I've successfully harvested yeast off my blow off tube, specifically WLP066 or I suppose any vigorously top fermenting yeast. Obviously make sure all is sanitized especially the blow off vessel, but because it blows off mostly yeast, what is left in the blow off vessel is super clean and barely needs to be washed. cheers!

[@Rtstrider]

Took some inspiration from this video and decided to rack some wort onto a full yeast cake today from a prior brew. Holy moly it's insane and FAST!!!! Thanks for all of the work put into these videos!

[@burlinghomebrewing]

I’m in the harvesting from starter camp. Do people still make starters? If you do, not sure why you wouldn’t harvest this way if your batch size is 5g or less.

[@balrog006]

I always overbuild my starters to harvest a pure sample. I also harvest from fermentation, Depending on what I brew with the used batch and what I want to make, I’ll either use the salvage yeast or the overbuild.

[@retheisen]

His mantle was full of personality.

[@paskrell]

Schlenkerla helles is a beer pitched with their märzen smoke beer yeast. It gives it a slight smoky note without being a smoked beer. Great beer!!!🍻

[@orange-micro-fiber9740]

When does a slurry expire? I used a harvested a cream ale a few months after previous pitch. I did a starter. It was gross (though a bit of orange juice made it tolerable insyead of dump able.)

[@balrog006]

Commercial packs are either 4-6 months. You can probably get about that, with great sanitation maybe a little longer-but viability will be very low and you have to start with a very small starter and build up several times

[@mb5o]

Over the years I have re-pitched yeast over and over. When the characteristics (taste, clarity, etc) of the latest brew become too different from the desired results, I use a new pack of yeast. For the last while, I have been using Kveik yeasts which have been quite hardy and retained steady characteristics through the repitches. I have collected the yeast from the bottom of the fermenter or the top of the krausen, and the resulting beers have been great, seemingly independently of the pitching rates (as stated in kveik yeasts documentation). It is worth trying new yeast, but when I find one I like, I re-use the hell out of it.

[@JohnDoe-es5xh]

If we brewing the same sort / type of beer again, we leave the remainig yeast slury from the last brewing in the keg. That works also very well under pressure fermentation.

[@garyelderman8391]

Would it lengthen storage life if dormant yeast was put in sanitized jars and then vacuum sealed before refrigerated storage?

[@balrog006]

Or likely by any measurable amount. Factory fresh yeast packs are sealed and their vitality is only 4-6 months

[@johnp.turner2000]

My question Am I able to harvest yeast from wine and make beer with it?

[@balrog006]

You can, it will ferment. But it wouldnt likely be any good, wine yeast is for wine not beer

[@vexy1987]

If homebrewers are throwing away yeast strains after 5 generations, how on earth do commercial brewers maintain heritage strains longer term? How was this done in the past prior to refrigeration/freezer tech? Which also begs the question, what did brewers brewing >1.070 OG beers do to maintain their lineages? Or were brewers just making beer with off flavours, and punters had low expectations for their premium beers?

[@donkeykongcounty2445]

Breweries have access to laboratories and very smart people who know what they're looking at under a microscope.

[@balrog006]

Breweries overbuild their yeasts and store a father yeast sample. The use the splits from the overbuild to ferment batches with, and repurchase on slurry for a few generations usually the same beer or progressively heavier/darker ones. After 5-10-20 uses the yeast is done and discarded. They then go back to the reserved father yeast sample and either draw off some and build it up to a pitch or build a starter with it and split it. Then saving another father portion they use the other portion to brew with, wash rinse and repeat, over and over.

[@chrisblake6]

Great video lots of good info- I rinse and reuse all my Yeast usually up to 5 pitches. My question is how long can it stay in the fridge between beers? I've heard a month before but how much longer do you think it could go safely?

[@donkeykongcounty2445]

Personally I wouldn't push it for more than a couple weeks with a lager and 3 to 4 with an ale strain. Kveik is weirdo shit that will live forever so go nuts.

[@balrog006]

You’re viability will be really low, but I’d say 3-4 months, maybe 6 at max

[@DimpieDeBruyn]

Been doing it for years 👍

[@coolieo5000]

Would love to see an experiment with high dry hopped beers washing Vs not washing the yeast. Is it something that's been done?

[@Margarinetaylorgrease]

I used to strain my through a 200mesh hop basket thing. Had to shake it a bit but most of the hops got left behind

[@CTP-bbq-HundHutte]

How long does he keep a jar in the fridge? Sorry if I missed that….

[@philjohnwilliams]

I have used yeast that had been in my fridge for 6 months. Use an online pitch calculator to ensure you make an appropriately sized starter.

[@JeffTheHokie]

@@philjohnwilliams I got an infection once that way. I used a big, loose jar,kept it in the fridge too long, opened it too many times, scooped the slurry out with a santized spoon, and probably allowed too much oxygen into the starter. Now I save my slurry in capped bottles. Open it once, and either use the whole bottle or dump the leftovers. Dumping the leftovers isn't wasting anything because you can get more from the new batch you are brewing. Remember, mason jars only seal under vacuum which you don't have, and every time you open a container you expose it to oxygen plus whatever germs may be floating in the air. Minimize exposure or you risk infection.

[@1964mjc]

300ml pet Soda bottles capped cleaned and sanitized make excellent little yeast storage containers..

[@normodegard183]

Like

[@tman9338]

I’ve washed yeast up to 5x using rinse method Emmmit video with 5 g and 3g carboys. Only brew high gravity beers 1.074 to 1.83 and just overpitch with no problem. Only issue was yeast going bad due to sloppy sanitation ( filtered water rinse) versus boiled water.

[@redheadsg1]

I harvested yeast 2 times but didn't reuse them yet. I was also cleaning/washing or separating yeast from trub and separation process is a bit annoying because i used a lot of distilled water (a important information left out of this video) that together cost same as 1 packet of dried yeast Kveik. So currently i don't know if (for me) harvesting and cleaning yeast if actually worth it.

[@cliff3033]

Another great video thanks guys. How does Jordan aerate his wort before pitching harvested slurry? Is pure oxygen required?

[@1964mjc]

Brew in kegs under pressure serve from keg with floating dip tube straight off yeast (in fridge) about gen 3 or 4 (of same or similar type eg us-05 on pale ale and ipa and pacific ale I put all in same class - same with any of the lagers using w34/70. Eventually there’s too much yeast so I O2-free closed transfer to another keg.) when starting to become “flavour muddled” I use new yeast (often found this to be about gen 6) . If I dry hop heavily the above becomes too tricky, unless next beer has same or similar hop (eg cascade and Amarillo or citra mixed can create a “new flavour” - but of course unrepeatable !! I Do sometimes save in jars but only for specialty yeast always build a starter (and sometimes overbuild starter to save half before the pitch) to make sure ok and take a sample of starter to taste test - if just tastes yeasty I pitch the starter (not the tasting sample!) if anything off I don’t use it..

[@BrewabitRick]

Really interesting and really easy to understand. I’ve re used yeast loads with great results cheers guys 👍🍻

[@jgdudash]

Great video... Thanks! I have a different question that you may know the answer to... Instead of harvesting yeast why not just buy a pack of dry yeast and use a small portion to create a yeast starter. You could freeze the remaining dry yeast for use at a later date. This seems equally economical and easier than yeast harvesting. I am new at brewing so is there some reason that this is a bad idea?

[@simonboughton4705]

I use All Rounder fermenters, when I keg I leave the yeast slurry in the fermenter and under a bit of C02 pressure , then leave them covered with a blanket until I brew again. On brew day I simply open the top and pump the wort in. No cleaning of the fermenter, low risk of contamination as not actually bottling the slurry and beer is good.

[@methodandmadness1]

I typically make beers with an OG around 1.078 and will repitch from batch to batch, always with a starter to build it back up each time and what I think is reducing the stress

[@tim-tim-timmy6571]

To measure the amount of compacted yeast you have, with no marks on the jar, you could assume that the jar is a cylinder and calculate the volume based on radius and height. You won't have to open the jar and risk contamination.

[@natedizzy]

Awesome I've been using slurries for a while now due to my frugality, haha. Every nice to hear this info from a good brewer and I agree that strong batches are also no good for a repeat. Thanks!

[@Margarinetaylorgrease]

I’ve been using a separatory funnel and losing bit of the bottom. I also add a tiny, tiny amount of zinc.

[@PierceRandall-hf7vf]

I add some bread yeast while I boil the starter as yeast nutrient, but I've been thinking about adding zinc. How do you dose? Do you just use vitamins with zinc?

[@Margarinetaylorgrease]

@@PierceRandall-hf7vf I’m adding 0.1g of zinc sulphate to 1L of water and using 100ml of that water to give me 0.01g of zinc sulphate. Tiny weeny amount🥸 Might be worth checking the numbers is it’s just what I’ve pick up from a quick Google I also only airate my yeast and not my wort have tipped of the old beer and added about 1L of cooled boiled water. Due to foaming I’m try airating only the water now Apparently it’s spelt aerating.

[@reyn66]

I ferment in a keg. So it goes straight into a new keg with my wort. But before it goes in I give the yeast a taste. It may sound disgusting, but it will let me know if I have any off flavors or an infection. I've tried the harvesting method, and I have had bad beer come out of it. For me, the harvesting has too many variables to get an infection and/or bad yeast.

[@jgar538]

This was a great one. I used to save yeast slurry, but my house burned down and though I'm back in the saddle, I have not gotten back into the slurry reuse in the way I used to. I do remember some yeasts like the Belgian strains did not hang in there very well for any length of time. Cheerz.

[@donnhaviland9629]

I am going to try my first repitch of a slurry from a batch of german pilsner using cellar science german lager yeast. Fingers crossed!

[@makuseitse]

I have reused yeast more than 10 years. If its starts to get off-flavores then I star with new one. Usually 5 to 10 generations.

[@cain1s]

Thank you so much for this one, Martin!!! I've been wondering for a long time about the best and most reliable way to re-use yeast. Excellent information here!

[@ehhagen]

I rinse mine and let it crash it in a sanitized rectangular Tupperware for about 2 to 3 hours. Then jar it up. The pulls from that are so clean.

[@donaldmorrill1636]

I brewed on a ten barrel system twenty plus years ago. We re-pitched off the bottom of our fermenters 12 times before using new Yyeast smack packs.

[@kingquesoIV]

why do you keep sanitizing after opening the vessels instead of before?

[@danmartvk]

I do this all the time. I always make a starter though. 1-2l depending on the beer it is going in

[@Ulbre]

Back when I was in the Middle East our rugby club would brew in 220 litre barrels. We would leave the slurry in for a further 2 brews before emptying and cleaning. The beer always had the same consistency. Over an 8 year period we probably put down a hundred of those 220 L barrels each year.

[@patrickglaser1560]

Sounds like they didn't catch you

[@mikekeller5202]

Bloody good, what have you been brewing lately Martin?

[@cstardustc]

Would it be possible/advisable to freeze the slurry to keep it for longer? Effectively combining the method from a previous video. Also, is there a significant amount of trube(non-yeast or dead yeast particles) included in the slurry?

[@PierceRandall-hf7vf]

There's a whole freezing method on homebrewtalk. It works great, although I've never done it with trub from the bottom of the fermenter, just an overbuilt starter. I'd wash the yeast first if it's from a prior ferment, but I'm not sure how much of a difference it makes.

[@kyleleblanc4068]

I'm wondering....the formula was 100ml of slurry x2 for estimated cell count. However in my past experiences, yeast slurry that isn't thoroughly rinsed tends to have a significant amount of trub. There was no mention of this in the video.

[@AlexSpetz]

my exact thoughts too

[@eike7519]

Thanks for the great video. As a follow-up, it might be interesting to see how overbuilt starters compare to the harvested yeast, especially after a number of uses in starters. I personally use this method to maintain my yeast bank, and since I keep the conditions in each starter the same with enough fermentables, nutrients, and oxygen, I think I could keep the yeast as it was when packaged. But I haven't done the experiments to support that claim.

[@balrog006]

I just saw that exact experiment video linked below this one-it’s the next one I’m watching.

[@BrewingWithBrandon]

Based on what Jordan said in the video, wouldn't 400ml of slurry be a huge over pitch? I wonder if using less of the yeast slurry would have a different result. I've done back to back imperial stouts with the same yeast with good results. Great video as always Martin

[@MsPaulsgirl]

I use 15/30ml with no issues!

[@seriomarkj]

100% doing this for my next saison, need to collect that yeast

[@GodfreyTempleton]

Let's just get this clear, one syphons the fermented beer off, say into a keg, then keeps the remaining residue in a fridge then uses it straight into the next fermentation. Surely not, Shirley?

[@donkeykongcounty2445]

common practice in a commercial setting! Yeast will get transferred into a yeast brink for the next batch.

[@thekris4378]

A few times I’ve reused yeast. I have had success with medium OG beers. With higher abv meads, I’ve had one success and two that I’ve had to pitch some more yeast and it started up soon after.

[@captainsalmonslayer]

Pitched some voss slurry in a mead that was last used 13 months ago. Took longer than usual to kick off but had no issues.

[@JPch108]

mais de 200 vezes e 10 vezes o mesmo fermento...

[@SCROWMD]

Yup , good info. Thanks guys.

[@Styv93]

amazing video!!

[@tomwidauer8376]

I have just started to make overbuilt yeast starters and then keep a decent amount in the fridge. So far, it seems to work well. I'm not far enough in to pass judgement but I am on my 3rd NovaLager starter and so far, all is good. ATM, I have about 5 jars with yeast and two starters in the making. Yeast is the most expensive ingredient in beer. Ferment a Lager to recommendations and you use something like 3 packs of Dubbya (W34/70 for those not in the know) at A$9.50 a pop. So about 30 bucks for a beer, where the hops cost you $5 or 6 and the grain around $18 when using the good stuff (Weyermann Premium Pilsner). That is more than half the cost of a batch. I don't do this with all the yeasts I am using, mainly Lager yeast because it is the most expensive but I do have Nottingham, Windsor and US-05 as I use a fair bit of them too. If I use a yeast 4 or more times a year, it is worth keeping some. As for re-pitching, it scares the living hell out of me. I've done 3 dirty batches and had one fail. 1 in 3 is too much to gamble away 5 hours of work. I know people who backfill their fermenters up to three times and had no dramas ever but I don't think I could get myself to go down that path.