Using yeast cake instead of packets

[Murrayatuptown]

I have been reading all these posts about reusing yeast cake in subsequent brews.

The mess at the bottom of my carboy I learned how to clean out?

I suppose something that large might have a random amount of viable yeast...apparently at minimum, 'enough' to 'if you can't take the heat, stay out of the kitchen'.

Obviously (?) you just use what's there, or a portion?

Can it be refrigerated if not immediately using the just-drained carboy?

This sounds like a slippery slope to not worrying about the rules .

I know people acquire yeast from local breweries. I think there is no need to ask if people estimate how many yeast cells one has...or do they?

Thanks

 

[Jayjay1976]

I routinely save yeast from yeast cakes and reuse them without any trouble. I don't bother to wash the yeast either. I have successfully raised starters from 9+ month old saved yeast cake and fingers crossed have never had an infected batch. My advice is to ignore the traditional wisdom about not saving yeast from hoppy beers. I think the higher alpha acid content actually confers a degree of resistance to infection as hops are a natural preservative. I do not however recommend saving yeast from high gravity batches. The yeast will be really stressed by the high alcohol and IME require a lot of stepping up to get enough to pitch in a new beer, which unnecessarily increases your risk of infection. I have had some less than spectacular results and sometimes some off flavors when I really push my luck saving too many generations but overall saving yeast has been a big benefit to me and no dumpers so far.

Edit: I save my yeast in 4-oz mason jars and store them in the bottom drawer of my fridge.

 

[Murrayatuptown]

Thank you.

Looks like take 1/3-1/2 the cake (just like birthdays!) and not from high-gravity to lower and go lighter to darker in sequence are three points that stand out as worth remembering.

I think not having space to start another brew immediately makes this a theoretical question for me.

 

[kgav8r]

I just pitched my first harvest 3 days ago. I was nervous and unsure, but it bubbled vigorously and has sense slowed. I didn't wash and went directly from kegging the beer on to dumping the cake into sanitized containers. When the time came, I pitched about 12oz in my new brew. The gravities were very similar and my new brew was ~7.5 gallons. I didn't save enough to try it again, but I will likely get another generation after this fermentation completes and save more to experiment.

I've heard of people dumping the new batch directly on the old cake, but then read that this might be overpitching. I am not advanced enough to know about pitch rates. YMMV, but the method above is so far, so good.

 

[CaveHomeBrewing]

I do not however recommend saving yeast from high gravity batches.

What is a general rule of when the original gravity qualifies as a high gravity batch? ~1.065? Thanks for providing your process and insight. I was planning to do my first yeast harvest so this is a timely thread!

 

[VirginiaHops1]

1.065 or less seems reasonable and is the general recommended range you'll see online. Ideally I'd like to do a sub 1.060 batch if I was harvesting but I don't think 1.065 is detrimental. My batches are generally a little under 5 gallons because I ferment in kegs but I usually will split the yeast cake between about 4 mason jars when I harvest. You don't have to use IMMEDIATELY, they'll be viable for awhile. But I try to go through them fairly quickly, like within a few months. When I get down near the end of the jars I'll sometimes harvest again and start all over, but I've never gone past generation 3(yet). I actually just pitched a jar of harvested WLP007(gen2) yesterday on a beer I brewed.

I've really never had any issues harvesting yeast. I did recently have an issue on a batch with Omega DIPA done with a proper starter, so go figure. In terms of the cell count it really is a total guess. You just need to kind of guestimate it, and my ratio has worked fine for my normal gravity beers. If I was brewing a super high gravity TIPA or imperial stout or something I'd probably pitch 2 mason jars in.

Also, if you're harvesting you really don't want to dry hop, or if you're dry hopping transfer off the yeast before you do it. Also try to get as clean as possible wort into the fermenter(filtering out as much boil hop/trub as possible). It'll help you end up with the most viable harvested yeast possible.

 

[eric19312]

I use yeast cake all the time. Mostly repitches of US-05. I don't believe I have made a batch in excess of 1.060 in a long time and almost all my batches would be considered quite hoppy and have had no issues repitching yeast that included a heavy dose of dry hop pellet material.

I save my yeast cake in mason jars. Either quart or half gallon jars. I never rinse or wash the yeast and believe it is happier stored under beer not water. After harvesting the yeast into the jars it normally will compact and form two layers...the thick yeast layer and the beer over that layer. I understand there is viable yeast in that beer layer but I normally dump that measure a calculated amount of the yeast to pitch.

Typically I will use the cake within 1-4 weeks of harvest. Most of the time it will be about 6 days from harvest to repitch.

I have used a lot of different calculators to determine how much yeast to pitch but these days go with the yeast starter calculator in Beersmith. I have created a custom yeast ingredient called harvested US-05 with a volume of 1mL. I set the amount of yeast in that volume as 1 billion cells at harvest date and let Beersmith use the difference between brew date and harvest date to determine current viability and based on the recipe how many mL I need to pitch.

After I got a conical fermentor I was able to harvest remarkably cleaner yeast and changed my assessment of cell count to 2 billion cells per mL at harvest for this very clean yeast. However if I dry hopped during primary fermentation before harvesting I will back it down to 1.5 billion cells.

For a typical 17 gallon batch of 1.050 beer I will end up using about 300-400mL of yeast. This tracks pretty close to a rule of thumb I learned years ago from Basic Brewing Radio...1/2 cup of thick slurry for a 5 gallon batch. That worked for me quite well for years too and kinda gives you perspective on quantity you need...its not half or even a third of the cake much less than that.

 

[Tobor_8thMan]

When I repitch I'll use in lighter to darker SRM brews. If all the brews are basically the same SRM then the order doesn't matter.

Recommended practice is to let the yeast settle. Note the whiter layer on-top of the sediment? This is what we want to repitch. Decant or extract this white layer.

Of course, for the most part, no one does the above. They simply pitch the whole thing into the new brew (after pouring off the liquid).

 

[Tobor_8thMan]

Just remember to keep your yeast cake in an enviroment suitable for the yeast (clean, sanitized and cold) and don't wait too long to repitch. Yes, some of the yeast will die.

 

[Beermeister32]

I’ll step in here to say that we’ve all re-pitched yeast cakes before but it really isn’t the best practice.

Yes, there will be plenty of yeast to ferment the new batch.

You will however be carrying over all the trub from the previous batch over to the new batch. We usually stress out about getting beer off the trub then this procedure you end up with all the junk from the last batch added to your new batch!

Sometimes it produces good beers. Sometimes it produces sharp or soapy off-flavors.

So, I’d say if you want to re-use your yeast, learn some basic yeast separation/washing procedures for making your best beers!

 

[madscientist451]

This sounds like a slippery slope to not worrying about the rules .

I break a whole bunch of "rules" with beer yeast:
-I don't clean out the fermenter, I just siphon off the beer to a keg and then dump the next wort right in.
However I usually don't go more than two runs with the same "dirty" fermenter.
-Some yeast is supposed to be "top cropped" at high krausen, But I don't bother with that I just use the slurry.
-I quit washing the yeast years ago and haven't had any problems. Some people say yeast washing is an absolute necessity, but others say that the washing process is just an opportunity to contaminate the yeast with something undesirable. I take the lazy brewer approach when I'm saving the yeast, I just pour the slurry to a sanitized quart jar and store it in the fridge.
-I've saved yeast that was originally a dry product like US-05.
-If I make a starter, I don't cold crash and decant the liquid, I chuck the whole thing in.

 

[Murrayatuptown]

Thanks all.

 

[Beermeister32]

Heck on the other hand does it really matter? Dump it in..!

 

[eric19312]

Here is a picture of a jar of yeast I collected about 10 days ago. When I put it in the fridge it was a foamy but fairly uniform slurry. I collected this over about 3 yeast dumps, using my 3" sight glass brink. Once the jar was about full I mixed it well and put it in my keezer. After settling the gas came out of solution and the yeast separated from the beer. To pitch this yeast I would decant off 90% of the beer and mix the yeast up with remaining 10% of the beer to thin it out and retain some of the less flocculent yeast. Then measure out a calculated quantity.

Sharing the picture because I am frankly scratching my head about what part of that yeast looks like it would benefit from being washed, rinsed or otherwise bothered before using in my next beer?

 

[VirginiaHops1]

-I quit washing the yeast years ago and haven't had any problems. Some people say yeast washing is an absolute necessity, but others say that the washing process is just an opportunity to contaminate the yeast with something undesirable. I take the lazy brewer approach when I'm saving the yeast, I just pour the slurry to a sanitized quart jar and store it in the fridge.

Me too. I follow some rules when harvesting to try to get the most viable yeast, like not dry hopping on it or harvesting from high ABV batches but I don't worry about bringing a little trub over with it.

 

[Surly]

Using my conical I will dump grub before fermentation completes. Waiting a few days I will then send some grub to my sight glass. I then determine if it looks white and creamy. If not to what I believe is good enough I may dump it. Or, I may save it to a sanitized jar and set it aside.

Repeating until satisfied I then dump what looks like the best to a one gallon glass jar.

I may or may not add that first sample to the gallon jar.

When ready to reuse i decant all the beer I can and then add the rest to my fermentor.

 

[Codfishhead]

I’ve reused my yeast forever. Tried all kinds of things from dumping on older cakes to washing. All worked but that doesn’t mean it’s best practices. Yeast is very fragile and needs to be in an optimal environment with lots of nutrition. Reason I now only make step up starters instead of risking off flavors and possible infections. Save a small amount from a new yeast package and make a starter. Then save a little when you dump it and make another starter from that. This way you’ll always have the same fresh healthy yeast.

as fir cell counts, over pitch if that’s a concern. Really only neg I’ve found from over pitching is a little less residual sugars in more alcohol.

 

[VirginiaHops1]

I’ve reused my yeast forever. Tried all kinds of things from dumping on older cakes to washing. All worked but that doesn’t mean it’s best practices. Yeast is very fragile and needs to be in an optimal environment with lots of nutrition. Reason I now only make step up starters instead of risking off flavors and possible infections. Save a small amount from a new yeast package and make a starter. Then save a little when you dump it and make another starter from that. This way you’ll always have the same fresh healthy yeast.

as fir cell counts, over pitch if that’s a concern. Really only neg I’ve found from over pitching is a little less residual sugars in more alcohol.

I'm seen plenty of people post about using this method and it seems fine. More work though, making a starter for every beer. I would only do this if I ran into issues/noticeable off-flavors harvesting & reusing and thus far I can't say I have.

 

[Pappers_]

I suppose something that large might have a random amount of viable yeast...apparently at minimum, 'enough' to 'if you can't take the heat, stay out of the kitchen'.

If you use it fresh, it has way more viable yeast than from a packet. Think of it this way - you made a giant 5 gallon starter. I routinely use the yeast from a previous small OG batch to ferment a bigger OG batch - like going from an American Pale Ale to an American Barleywine.

 

[Surly]

I'm seen plenty of people post about using this method and it seems fine. More work though, making a starter for every beer. I would only do this if I ran into issues/noticeable off-flavors harvesting & reusing and thus far I can't say I have.

You give me an idea. I brew a series of House Brews. I like to replicate and standardize my styles.

I will consider brewing separate batches of the same style in series. Using different yeast handling processes and then comparing may be of interest.

 

[Jayjay1976]

If you use it fresh, it has way more viable yeast than from a packet. Think of it this way - you made a giant 5 gallon starter. I routinely use the yeast from a previous small OG batch to ferment a bigger OG batch - like going from an American Pale Ale to an American Barleywine.

I have a few favorite stout recipes, all around 1.060, that leave behind an excellent yeast cake to pitch a well-aerated imperial strength stout onto. They always finish out without hint of a stall, I contribute that to the abundance of healthy cells and nutrients in the yeast cake.

 

[VirginiaHops1]

You give me an idea. I brew a series of House Brews. I like to replicate and standardize my styles.

I will consider brewing separate batches of the same style in series. Using different yeast handling processes and then comparing may be of interest.

Absolutely report back if you do that. I'd like to know if you perceive any differences. There are so many variables like that I'd like to test but never can bring myself to brew the same recipe repeatedly

 

[JimRausch]

My winter series of lagers start off with a Vienna with an OG of around 1.055. When that is finished and I rack it for lagering, I save the slurry- usually wind up with 3 qt. mason jars stored in the fridge. I pitch one of those jars to my Marzen with an OG of 1.060-1.065 and the remaining 2 quarts to my Bock or Doublebock with an OG of 1.075-1.085. Have done this with dry 34/70 yeast and several different varieties of liquid lager yeasts.

 

[cmac62]

If I'm not trying to hit specific style guidelines I don't even worry about light to dark, the minimal flavor and color will not likely make a significant contribution to a 5 gal batch. I also just shake up the slurry, pour it into a sanitized jar and store in the fridge. When ready to use I will take it out, decant, let it warm up and just pour into the new wort. works for me and no issues with off flavors as yet.

 

[odie]

i will dump directly on the old yeast and trub cake in the fermenter if i have a fresh brewed beer ready the same day im kegging from that fermenter. don't clean the fermenter, just dump the fresh kettle in.

otherwise i will harvest the yeast cake in several small mason jars and reuse later for a similar beer.

 

[jerrylotto]

Noone is talking about reactivating the cake. My plan was to put the mason jar contents into a mixer with a whisk attachment and 1/4 cup of DME and aerate it as it warms to room temp while I'm cooling my wort. If I don't see activity after a couple of hours of that, I will flush it down the toilet and pitch dry.

 

[eric19312]

Noone is talking about reactivating the cake. My plan was to put the mason jar contents into a mixer with a whisk attachment and 1/4 cup of DME and aerate it as it warms to room temp while I'm cooling my wort. If I don't see activity after a couple of hours of that, I will flush it down the toilet and pitch dry.

Wow I don't think you want to hit the yeast with that aggressive of mixing / stirring. An occasional gentle swirl of the jar should be plenty of aeration at this point.

 

[jerrylotto]

OK - I put the mixer on the "low"setting

 

[odie]

If I don't see activity after a couple of hours of that, I will flush it down the toilet and pitch dry.

You are likely tossing a good viable yeast.

I harvest yeasts from my fermenters into a small mason jars and have stored close to a year in some cases. Even high gravity Belgian and RIS yeast cakes with successful re-pitching. I now have way more jars of yeast than I can use since I usually get 2-3 half pint jars of each harvest. I need to retire the older jars even though they are likely perfectly fine still.

All I do is decant the beer on top of the jar of yeast and then top with fresh wort from the just filled fermenter, swirl and dump in the fermenter. The yeast is dormant from sitting in the fridge at near freezing temps. It can take as much as a day or two before you will see active fermentation.

 

[Jayjay1976]

^^This guy is right. I end up dumping jars long before they are old enough to be questionable just to make room to store fresher yeast. TBH, I probably end up dumping more than I use but I always have yeast on hand and I might only purchase a particular strain once per year. My two Belgian house strains, 1762 and 3522, I've been saving and re-pitching for a couple of years now.

 

[odie]

If I have more than one jar of the type I'm wanting to use, I'll grab the freshest one first, open and sniff test and pitch it. bad sniff...dump and grab the next freshest one and repeat...worst case i dump all of a certain type and pitch a new pack of dry yeast and start the harvest cycle from scratch.

I just pitched a jar of harvested Kolsch yeast from last Feb that was a re-pitch in itself, so 2nd or 3rd generation already. I still had 2 dry packs of Kolsch yeast in reserve but wanted to see what would happen. It's chugging away...will see how it tastes in a couple months.

 

[odie]

Here is a picture of a jar of yeast I collected about 10 days ago.

View attachment 717171

do you filter or screen all the kettle wort into the fermenter? I've started doing that and I pretty much save the entire fermenter cake and it looks about like what you have. A huge cake of pretty clean yeast cake with little to no trub at all. No washing or decanting needed.

 

[eric19312]

do you filter or screen all the kettle wort into the fermenter? I've started doing that and I pretty much save the entire fermenter cake and it looks about like what you have. A huge cake of pretty clean yeast cake with little to no trub at all. No washing or decanting needed.

No filters. I whirlpool through my CFC back into the kettle to drop kettle temp to desired hop steep temp and then whirlpool with the hops for a few minutes. I then let the kettle settle for at least 15 minutes. Then I slowly pull from the corner of the kettle through CFC into fermentor. I have one of those Spike kettles with the two tier bottom, lower tier holds the cone and I pull wort from the upper tier. Really does a nice job leaving hops and hot break in the kettle. The cold break will mostly go into the fermenter since most of it precipitates in the CFC. If I have time I will dump whatever cold break collects at the bottom of the cone before pitching yeast.

 

[mattdee1]

The only kind of "reusing" I do anymore is done by over-building yeast starters by about a liter or so, and saving that in the fridge to form the basis of a future starter. My most recent batch was a 10gal pale ale (~1.050) that used some WLP001 I saved from an overbuilt starter 7+ months ago and had stored in the fridge. That saved yeast was 3rd or 4th generation from the original retail vial. I made a starter with it, which took a bit longer than usual to ferment out, but the beer is flowing now and turned out great.

I've reused S05 several times using various methods (harvest and store, pitch right on the cake, etc.) and I've had at least 3 batches where the beers ended up with a weird Belgian character to them. Still totally worth drinking but not what I want or expect out of S05. I assume it was caused by some kind of contamination or maybe underpitching or whatever... I don't really care because I've resolved to never fart around trying to get more than one batch out of a yeast packet that costs $3.

 

[Immocles]

I've reused S05 several times using various methods (harvest and store, pitch right on the cake, etc.) and I've had at least 3 batches where the beers ended up with a weird Belgian character to them. Still totally worth drinking but not what I want or expect out of S05. I assume it was caused by some kind of contamination or maybe underpitching or whatever... I don't really care because I've resolved to never fart around trying to get more than one batch out of a yeast packet that costs $3.

I've had very similar experiences. I repitched with great success until I didn't. After having three odd tasting batches in a few month span, I decided I would just stick to fresh packs of dry yeast (with a few, small exceptions). Maybe my sanitization is mostly to blame, but for a relatively small price tag, I will take it over being disappointed in a batch.

 

[mattdee1]

I've had very similar experiences. I repitched with great success until I didn't. After having three odd tasting batches in a few month span, I decided I would just stick to fresh packs of dry yeast (with a few, small exceptions). Maybe my sanitization is mostly to blame, but for a relatively small price tag, I will take it over being disappointed in a batch.

Exactly. It's not that there is no way of making it work, and to those who get it to work perfectly every time, good for them I guess.

But when you consider the number of hours that you invest into a batch of beer from lighting the kettle to cleaning the fermentor after packaging, $3-$4 savings seems like a poor balance against the added risk of problems. The only thing I'm annoyed at now is that I let myself get burned 3 times before finally saying "screw this s&*t" and putting in place the rule that I will buy fresh packs of dry yeast every time. The added convenience of it is easily worth the piddly cost; the added reliability of it is just icing on the cake.

 

[eric19312]

Well I decided to brew a few lagers over coming months and first batch started with dry yeast...needed 6 packs of Saflager 34/70. Got a good price on the packs but it was still almost $30. I'll absolutely harvest and reuse if yeast behaves as expected.

 

[Tobor_8thMan]

I will repitch up to 5 times depending on the gap between repitching. As an example, this past summer, I was busy with other summertime things and didn't brew as much as planned. I only repitched 1 yeast strain 3 times instead of my normal 5 times as the gap between brewing was, IMO, too much.

 

[RePete]

This past year I've been brewing almost every weekend, and doing as some here have suggested...just drain the beer from the fermenter into a keg, and then pour the new wort into it. It has worked. I'm on the 3rd batch for the present yeast cake. Normally, I get to a point where I just want to do something else, and pitch new yeast then. I have stopped saving used yeast beyond just keeping the current cake going. I had some jars saved up in the fridge, but recently dumped those. The yeasts I use are easy enough to find, and I figure that once it gets beyond a few generations, may as well just dump it and start over.

 

[kpsalerno]

I reused a S-04 slurry eight generations in a year, repitching 1 Cup for 5.5 gallon standard strength batches, then topping off the jar with yeast cakes from each subsequent batch. Never had an issue, and one of the beers was entered in a competition and did well.

I also kept a W-34/70 slurry for 12 months to the day before repitching 2 Cups for the first time and experienced a huge lag of 96 hours at 54F with a standard strength batch before I finally saw krausen formation and any airlock activity. High krausen and steady airlock activity took 120 hours. I read somewhere above that is to be expected when you keep a slurry dorment that long.