Reusing Yeast

[redrocker652002]

So, I just finished bottling my latest batch and got the thinking. There was about an inch or so of liquid sitting on top of the white cake at the bottom of the bucket, I am assuming that was the yeast. So, I shook it up a bit and got it mixed in with the leftover beer. I did not have the time to look for mason jars nor the knowledge of what to do with it, so I dumped it. But then, as I enjoyed a beer and sat in the backyard I got to thinking about the various threads I read about reusing yeast. Would I simply have been able to put that in mason jars and pop it in the fridge? Dry yeast is only 5 bucks or so, so my question isn't about saving money, but more about reusing instead of just dumping. I am going to do a brew next week if I have time, and I will more than likely be using Bry97. I am curious what I need to do, and to check to make sure it is still viable. Also, how long will it keep in the fridge in mason jars? Any input for the novice is greatly appreciated. Rock On!!!!!!!

 

[bellhp]

That is what I have been doing... swirl it and pour it in jars ... leave lid slightly loose for a day or two ... longest I've kept and reused so far was 5 weeks .

 

[RM-MN]

Dry yeast is only about $5 so you pitch that packet into a 5 gallon batch. When that is done and bottled you swirl up what's left and divide it into 4 mason jars. OK, now you have $20 worth of yeast to put into the fridge. You then pitch each of those 4 into a separate 5 gallon batch, let if ferment and salvage that yeast. Now you have 16 jars with yeast in them, each worth about $5. That should be worth about $80 and in total you have saved $100. Now is it about saving money?

Eventually you will need to separate out the trub and sooner or later it might be wise to buy a new packet as the yeast will have mutation drift.

 

[hottpeper13]

I don't save all of it but just enough to repitch next batch and most of the time repitch same day beer is racked off. I repitch up to 4 times because I have 6 strains in the fridge from overbuilds and need to feed them at least once a year.
Just ordered some BRY-97 yesterday and will be adding that to my inventory. currently using Voss in my IPA's and have been very happy with it,but am going to split a batch and see which one wins.

 

[redrocker652002]

Dry yeast is only about $5 so you pitch that packet into a 5 gallon batch. When that is done and bottled you swirl up what's left and divide it into 4 mason jars. OK, now you have $20 worth of yeast to put into the fridge. You then pitch each of those 4 into a separate 5 gallon batch, let if ferment and salvage that yeast. Now you have 16 jars with yeast in them, each worth about $5. That should be worth about $80 and in total you have saved $100. Now is it about saving money?

Eventually you will need to separate out the trub and sooner or later it might be wise to buy a new packet as the yeast will have mutation drift.

Good call. And thank you for putting it into numbers. I am that kinda guy. LOL.

So, I guess my next question would be, how long can it stay in the fridge? I brew once every month or so. So, 4 jars would be about 4 to 6 months worth of supply if it keeps that long. If not, I will just harvest 2 jars maybe. Either way, it could be fun to give it a go. Also, can I check its health before I put it in my beer by adding some DME to the jar and see what happens? If so, how much is good and how much is too much? I know, lots of stupid questions.

 

[redrocker652002]

I don't save all of it but just enough to repitch next batch and most of the time repitch same day beer is racked off. I repitch up to 4 times because I have 6 strains in the fridge from overbuilds and need to feed them at least once a year.
Just ordered some BRY-97 yesterday and will be adding that to my inventory. currently using Voss in my IPA's and have been very happy with it,but am going to split a batch and see which one wins.

So your yeast lasts a year in the jars in the fridge? Or am I reading it wrong?

 

[Closet Fermenter]

I have had mixed results with reusing yeast. Most likely, it’s been my procedure, or keeping it to long, or a combination of the two.
I’ve had some that worked fairly well. A couple weeks ago, I used yeast from the fridge from October and got nothing.
My best results have been running fresh wort right in on top of the yeast cake in the fermenter. Here, I used a closed transfer to my purged keg during the boil of my next batch. I left the fermenter sealed until I had chilled my wort. I pulled the tapping head, dumped the wort directly into the fermenter, and replaced the sanitized tapping head back in place. It started up so fast that I had to keep pulling the relief valve before I could get the keg in location and connected to a blowoff.

 

[odie]

I save yeast cake in mason jars. I've used yeast cake that I had in the fridge for over a year with good results.

Yeast is very resiliant when kept properly.

 

[wdavis2003]

I have had mixed results with reusing yeast. Most likely, it’s been my procedure, or keeping it to long, or a combination of the two.
I’ve had some that worked fairly well. A couple weeks ago, I used yeast from the fridge from October and got nothing.
My best results have been running fresh wort right in on top of the yeast cake in the fermenter. Here, I used a closed transfer to my purged keg during the boil of my next batch. I left the fermenter sealed until I had chilled my wort. I pulled the tapping head, dumped the wort directly into the fermenter, and replaced the sanitized tapping head back in place. It started up so fast that I had to keep pulling the relief valve before I could get the keg in location and connected to a blowoff. View attachment 817380

My results have been great using the same method. I typically plan my brews so that I can re-pitch on top of previous yeast cake. For example, brew a pilsner with S-23, then when I keg the Pilsner pitch a Cold IPA on top of the S-23 yeast cake. Or my latest, best example, brew an Irish Red Ale, then pitch a Double NEIPA on top of the Irish Red Yeast cake.

For the OP, I usually rack my beer into keg without introducing O2 and leave the yeast cake in the fermenter, in the fermentation chamber for a week until I brew the next batch. Haven't kept it longer then that.

 

[hottpeper13]

So far (since 2013) i've only composted 2 strains that were 1 yr or close and those were Conan and Joy Stick. I don't count the Hornindal cause it comes with 2 or so bacteria and that one formed a pelical in 2 mos. My Saison strain was 4 years old and I did the 15 ml to 150 ml to 1500 ml. It took 3 days for sediment to form in the 15 ml tube.

 

[Closet Fermenter]

For the OP, I usually rack my beer into keg without introducing O2 and leave the yeast cake in the fermenter, in the fermentation chamber for a week until I brew the next batch. Haven't kept it longer then that.

Now that’s something I have not even considered. What a wonderful idea! To be honest, given the limitations of my brewing/ fermenting areas, it’s a bit of a hassle to coordinate a slow, gravity transfer and brewing at the same time. Also, I would have preferred to get the wort temperature down just a little more before dumping it in on the yeast.

 

[balrog]

Sanitation is key to reuse. And making starters is very helpful, but many simply tell of saving a cup of the fermentation dregs and pitching that no issues. But sanitation. Dust in the air has bacteria and it settles on everything.

 

[whattabrau]

Yes, harvesting and reusing yeast is easy.

First, I separate yeasts into top and bottom croppers.

For top croppers you spoon the foam off the fermentation into a large jar, let it settle, pour into a smaller jar, let it finish fermenting, close the lid tight, and put it into the fridge (and if it's a diastatic yeast burp it regularly at least for the first few months of storage!). Top-cropped yeast lasts a really long time. I'm an outdoor brewer, and I just last week started using my top-cropped yeasts harvested in September/October.

Bottom-croppers you harvest, you guessed it, from the bottom. If you have a fermentor with a yeast dump valve, use that, but I don't, so I use a spoon after racking the beer off. You generally want the mid-layer of the yeast cake. The bottom is trub, and it feel significantly different. The top layer is late-flocculators, so unless you're conditioning your yeast for poor flocculation, avoid it. Bottom-cropped yeast doesn't last very long, probably because it sits for quite a while in the warm fermentor. I'd say four weeks is the max you want to store it (maybe more if you have a yeast dump valve), and two weeks is even better.

Bottom-croppers stay good for much longer if you use the "overbuilt starter" method, where you make a larger-than-necessary starter and save half. I generally don't use the technique, because it's extra work and cost, and instead try to plan my bottom cropping yeast brews so that they're reasonably back-to-back, or even directly back-to-back.

To use a harvested yeast, I decant the liquid -- for some top cropped beers it's close enough to the target beer that I drink it instead of wasting! -- and replace it with chilled pre-boil wort. Once the batch is ready to accept the yeast (boiled, chilled etc.), the yeast is usually already going and I pitch the whole thing.

You can pretty much always safely use yeast for a few generations. I like to use top-croppers indefinitely. At about 10 generations you need to start adding zinc to ensure full attenuation; I use servomyces which has a dose of 1g/hL, so a small packet lasts "a while" and is essentially free. Occasionally, if you start detecting sourness you have to wash the yeast with acid; it's not difficult, but a pH meter is a requirement. Of course, it's up to you if you find "yeast-hacking" worth your time and interest, and buying a new yeast after a few generations as "insurance" is a perfectly valid approach too.

 

[odie]

For the OP, I usually rack my beer into keg without introducing O2 and leave the yeast cake in the fermenter, in the fermentation chamber for a week until I brew the next batch. Haven't kept it longer then that.

I do something almost the same.

I ferment and serve in the same keg. when the keg finishes, I do not open it. I leave it sealed with whatever yeast did not get blown out with the last glass of beer. It stays cold until it's time for fresh wort. I just open the keg and pour fresh wort in and let the leftover yeast go back to work.

I just started another hefe on a 5th generation keg.

 

[odie]

And making starters is very helpful, but many simply tell of saving a cup of the fermentation dregs and pitching that no issues.

That is all I do. If I am using saved yeast cake from a mason jar, I just direct pitch it. Probably around a 1/4 - 1/2 cup worth of compacted yeast cake.

I think some of those liquid yeast you can buy today are meant for "direct pitch", no starter. The old "smack packs" were that way.

 

[scogan]

I have pitched straight on the dregs .It took off in an hour and finished in about 48 hrs with a bit of foaming into my blow off tube .Next time I will follow the suggestion I was given - draw off half of three quarters of the trub/yeast first then pitch.

 

[wdavis2003]

Now that’s something I have not even considered. What a wonderful idea! To be honest, given the limitations of my brewing/ fermenting areas, it’s a bit of a hassle to coordinate a slow, gravity transfer and brewing at the same time. Also, I would have preferred to get the wort temperature down just a little more before dumping it in on the yeast.

It works great and it's usually under 5psi or so of pressure for the week. Not sure if that hurts the yeast but it's something I've wondered. I just pull it out of the fermentation chamber on brew day so I can get the yeast up to normal pitching temperature

 

[wdavis2003]

I do something almost the same.

I ferment and serve in the same keg. when the keg finishes, I do not open it. I leave it sealed with whatever yeast did not get blown out with the last glass of beer. It stays cold until it's time for fresh wort. I just open the keg and pour fresh wort in and let the leftover yeast go back to work.

I just started another hefe on a 5th generation keg.

That's not a bad idea. I ferment in a Fermzilla and I've been tempted to just serve out of it.

And I've been tossing the yeast after the second batch but I cringe as I pour it down the drain.. Seems like such a waste

 

[Closet Fermenter]

And I've been tossing the yeast after the second batch but I cringe as I pour it down the drain.. Seems like such a waste

When I do pour yeast down the drain, I tell myself it’s not a waste; we’re on a septic system, so it’s just contributing to the cause by boosting the community of those serving us.

 

[redrocker652002]

OK, so first off thanks to all who replied. I have gotten some great info. I think I am going to try something on this next round. My thought is, I am going to brew a simple single hop kit from MoreBeer. I am going to use the packet of Bry97 I have and do a 2 week fermentation and dry hop. My thought is, I will brew my next batch, more than likely a similar using just a different hop, bottle the brew in my fermenter and then pitch the new wort on the yeast that is in the bucket right after. Of course, check the temp and give the yeast a swirl in the bucket before I pitch the new wort. Does anybody see a flaw in this? I figure then keg the second batch, try and save the yeast in mason jars and put in my fridge. I will date the jars and anything over 6 to 9 months I will try a starter first. Comments welcomed.

 

[ebbelwoi]

If I'm planning to reuse the yeast, I don't dry hop that batch. I also make sure to limit the amount of break material that gets into the fermenter. For me, it's too much extra crud to worry about. Others may not see a problem with it, though.

 

[beren]

Just chiming in, this works really well: Maintaining A Healthy Yeast Bank Long Term when I get new yeast I make a starter and decant then split it up. 10 small vials get glycerin and go into the freezer. When you want to use them get some wort and dump the vial in. No generational mutations and the vials are good for a couple of years in the freezer. I’ll be up to 70 vials with 8 strains this week, and 3 more yeasts to do after that. First generation pitch is under $2 for the yeast pack and dme, and after that just the cost of 100g or 1l of wort from a brew. Best part is no need to ship or drive to the LHBS to get liquid yeast in summer.

 

[theredviper]

I ferment and serve in the same keg. when the keg finishes, I do not open it. I leave it sealed with whatever yeast did not get blown out with the last glass of beer. It stays cold until it's time for fresh wort. I just open the keg and pour fresh wort in and let the leftover yeast go back to work.

I have done this as well but don't have a lot of fridge/kegerator space. Do you think it's ok to pull out the spent keg and leave it sealed closer to room temp for any length of time?

 

[beren]

I have done this as well but don't have a lot of fridge/kegerator space. Do you think it's ok to pull out the spent keg and leave it sealed closer to room temp for any length of time?

From what people have said it will only last a few weeks at most.

 

[Teacon7]

Long time lurker/skimmer, first time poster. Thanks to all for sharing your homebrew wisdom with the world.

I have a question about re-using yeast... How long will 'saved' yeast stay good for?

Here's why: I've never re-used saved yeast before. I tried saving some from a brew a while back ("Omega Yeast OYL-004 - West Coast Ale I" from a kit... it turned out great). I poured the leftover trub into a sanitzed mason jar. Once it had settled, I poured the top layer of liquid (and a bit of the 'fluffy' looking sediment) into another sanitized mason jar, and stuck it in the back of the fridge. It's been there for just over a year. I haven't done anything with it since, and there's been all sorts of other groovy stuff in the fridge. The batch turned out awesome and I'm ordering the same kit again. Is there some kind of statute of limitations on how long 'saved' yeast will last?

I'd like to start re-using yeast, but I've still got a lot to learn. I don't brew frequently enough to keep re-using it on a (for example) quarterly basis. I'm obviously okay with the cost savings, but don't want my ignorance to screw up a grain bill. How long will it keep in the fridge? Should I try again with THIS batch's yeast, and save it better somehow?

 

[whattabrau]

I have a question about re-using yeast... How long will 'saved' yeast stay good for?

It depends. If you harvested it from the bottom of the fermentor, I wouldn't give it more than two weeks. If you top-cropped it or overbuilt a starter and kept chilled, it *might* last a year. I just took my "house" BE-134 out of winter slumber a week ago; it had been top-cropped about 9 months earlier, and it did took slightly longer than usual to get started (almost 24h), but then it did the job.

I'd like to start re-using yeast, but I've still got a lot to learn. I don't brew frequently enough to keep re-using it on a (for example) quarterly basis. I'm obviously okay with the cost savings, but don't want my ignorance to screw up a grain bill. How long will it keep in the fridge? Should I try again with THIS batch's yeast, and save it better somehow?

You can always make a starter to see if the yeast is still alive. I usually take some wort out of the mash (cheaper than DME), heat it to suit my paranoia, chill, decant the liquid from the jar, and pour the fresh wort in. If I'm fairly confident with the yeast health, I do the above from the current brew, otherwise I think ahead and do it for a yeast I plan to use soon.

 

[odie]

I've saved yeast cake from the bottom of my buckets and kept them in mason jars in the fridge. Some of those I've pitched a year later with no issues.

Every jar gets the sniff teste before pitching.

 

[beren]

If you freeze your yeast like the link I posted it should last for at least three years.