Checking my understanding regarding harvesting yeast

[Steve Broady]

I’ve read through a bunch of threads trying to glean information about harvesting yeast. I think I’ve got it, but I’d like to run this by someone and check myself. Of course, I can just try it and see what happens, which I’ll likely do as well, but I’ve got some down time while the still heats up, so why not ask?

I have a bourbon mash (fermented with S04) which has been in the fermenter for about a month. Settled nicely, just a tiny bit of something white floating on the surface. I strained off all the clear beer and am doing the stripping run now. The rest I’ve got in my fruit press with some fiberglass window screen, and I’m squeezing out as much as I can. The plan is to let that settle, rack off the clear beer on top, and add it to the low wines for the spirit run.

I’m thinking that I can then harvest live yeast from what’s left behind. As I understand it, it should be at the top of the custard, correct? Or have I got this all wrong? Assuming I’ve got it right, I would make up a starter from that yeast and pitch it in my next batch. I’m thinking the starter ought to be some of the wort, maybe mixed with water to reduce the concentration.

[Ben]

I’m thinking that I can then harvest live yeast from what’s left behind. As I understand it, it should be at the top of the custard, correct? Or have I got this all wrong? Assuming I’ve got it right, I would make up a starter from that yeast and pitch it in my next batch. I’m thinking the starter ought to be some of the wort, maybe mixed with water to reduce the concentration.

Yep. Grab a mason jar of that stuff and let it start to settle in the fridge. The yeast falls after everything else so it is naturally stratified to the top layer of solids in the fermenter, below the beer. Here's an illustration (it refers to sparged ferments rather than on the grain, but idea is same).

Decant the top layer, then the yeast into your starter, leave the grain behind. If some grain ends up in your starter it's no big deal.

You don't even need a starter, especially if you are working from a freshly completed ferment. Here is a slurry pitching calculator if you would rather not bother. https://www.brewersfriend.com/yeast-pit ... alculator/ (Select slurry from the drop down). If you don't want to settle, compact and decant your slurry, just double the volume it asks for.

Most of what we are doing is "high gravity ale" for the calculator, 1-1.25M cell pitch range.

[subbrew]

Another way it is sometimes done in beer brewing is called pitching on the yeast cake. It usually over pitches the yeast so I only do it if I am making a dark beer that is able to hide any off flavors by over pitching. But the process is to siphon off the cleared beer from the fermenter and pitch the new wort in the same fermenter with all the yeast cake still in the bottom. Ben's advise has more control.

From a practical standpoint putting a sugar head on spent grain is the same thing. The spent grain is full of yeast, the yeast cake if you will. When you dump sugar and water on that grain you putting wort on the yeast cake.

[still_stirrin]

I’ve read through a bunch of threads trying to glean information about harvesting yeast. I think I’ve got it, but I’d like to run this by someone and check myself. Of course, I can just try it and see what happens, which I’ll likely do as well, but I’ve got some down time while the still heats up, so why not ask?

I have a bourbon mash (fermented with S04) which has been in the fermenter for about a month. Settled nicely, just a tiny bit of something white floating on the surface. I strained off all the clear beer and am doing the stripping run now. The rest I’ve got in my fruit press with some fiberglass window screen, and I’m squeezing out as much as I can. The plan is to let that settle, rack off the clear beer on top, and add it to the low wines for the spirit run.

I’m thinking that I can then harvest live yeast from what’s left behind. As I understand it, it should be at the top of the custard, correct? Or have I got this all wrong? Assuming I’ve got it right, I would make up a starter from that yeast and pitch it in my next batch. I’m thinking the starter ought to be some of the wort, maybe mixed with water to reduce the concentration.

I’ve suggested to you before to look to homebrewing websites for brewing and fermentation guidance. HD is not the “complete source” for all info. Here’s a sample:

https://byo.com/article/harvesting-yeast-techniques/
https://beerandbrewing.com/yeast-harves ... s-time-to/
https://www.morebeer.com/questions/218



Steve, keep your mind open and learn to use your “tools”. You really don’t need spoonfeeding.
ss

[Steve Broady]

Steve, keep your mind open and learn to use your “tools”. You really don’t need spoonfeeding.
ss

I apologize, I didn’t think I was asking to be spoon fed. After your advice, though I’m not a beer brewer or drinker (for the most part) I have started reading a few other forums and web sites. To be honest, I often find that the information I’m looking for is even more challenging to find because I don’t know enough yet. However, I do try.

In this case, the process is new to me. I’ve certainly reused yeast in UJSSM and when making a sugarhead on spent grain. But I’ve never tried to harvest yeast after pressing, as I’m doing here. I’m still quite new to the hobby, and often I find that I’ll learn about something new to me but have to piece the process together from several different sources. Since I don’t know enough yet to be certain that I understand what I’m reading, I wanted to run it by people with far more experience and just verify that I didn’t miss or misunderstand something.

Worst case, I have plenty more yeast on hand. And obviously I can just try it and see what happens. Which is what I’ll do in any case, since I can’t see a reason not to. Just trying to make sure I’ve managed to correctly apply what I’m learning, and maybe have a chance to correct it if I’ve totally failed somehow.

[subbrew]

Keep asking Steve. To me the fermentation is the hardest part of distilling. There is a lot to learn, from water chemistry, to yeast biology, to environment management and more. And producing a good input is the most important part of a good output, crap in = crap out. I think your threads will help a lot of people new to the hobby

[MooseMan]

Steve I've been harvesting yeast from finished ferments for many years. From wine, cider and beer.

I find that from a healthy 5gal ferment, I can use the "Yeast cake" to get several new batches going.

For wine, which I generally ferment to a high ABV. 15+
Unless there's loads of fruit pulp in the bottom I'll use what lees are left after syphoning to pitch into 2x new wines.

For cider which I ferment with a common beer yeast called Nottingham, or notty, to approx 5.5-6% ABV, I can always get 6 or 7 new ferments going from the lees of just one 5 gal batch. Something to do with available nutrients I think.

For beers I do the same but often use for 3 new batches as needed. Never lager.

Absolute simplest way is to either put your new ingredients (Nothing hot, or you'll kill it! Yes I've done that...) directly on top of the existing lees left after syphoning, or separate and let settle a little, then pitch, as described by Ben.

Yeast from an existing, healthy ferment, is never a bad idea, and too much is never bad either.

[Dougmatt]

Steve, keep your mind open and learn to use your “tools”. You really don’t need spoonfeeding.
ss

I apologize, I didn’t think I was asking to be spoon fed.

I gotta say, while I respect your contributions SS, this was uncalled for. These discussion boards are for….

DISCUSSION.

I feel like Steve proposed a question with his planned solution and asked for feedback. Telling everyone to “do their research and stop asking for spoon feeding” IMO stops the discussion. The bulk of your response was really helpful, but would be great if we could lose the snide comments. If it wasn’t for questions, this board wouldn’t exist….

Keep asking Steve.

D

[Dougmatt]

Yep. Grab a mason jar of that stuff and let it start to settle in the fridge. The yeast falls after everything else so it is naturally stratified to the top layer of solids in the fermenter, below the beer. Here's an illustration (it refers to sparged ferments rather than on the grain, but idea is same).

NOYES.jpg
Decant the top layer, then the yeast into your starter, leave the grain behind. If some grain ends up in your starter it's no big deal.

You don't even need a starter, especially if you are working from a freshly completed ferment. Here is a slurry pitching calculator if you would rather not bother. https://www.brewersfriend.com/yeast-pit ... alculator/ (Select slurry from the drop down). If you don't want to settle, compact and decant your slurry, just double the volume it asks for.

Most of what we are doing is "high gravity ale" for the calculator, 1-1.25M cell pitch range.

This was a very useful post Ben. Thank you. I really listen when you start talking yeast (not that I always agree )

I tend to do multigenerational yeast ferments where I jump start my next ferment using the last ferment of the same batch (ie rum wash, siphon the wash out, strip, dump next batch + dunder on top of old yeast cake and keep going). I’ve done 5-7 generations without detectable issues. Any thoughts about how many generations you can harvest from or any concerns to be aware of harvesting yeast for use over and over?

[Bradster68]

Iv done some research and not much at this point. But from what iv gather from SS links ( which he's taken the time to share)
It varies from different yeasts and washes, mashes etc. No need for everyone to get butt hurt over a comment. As much as this may be aggravating (To some). It will make you more determined to seek out the answer yourself.
And at the "Least" your pointed in the right direction for your answerseveryone

[Dougmatt]

…….. … .. ..

[Dougmatt]

No need for everyone to get butt hurt over a comment.

If that was directed to my comment, then no one is “butt hurt”, however IMO ss’s comment was uncalled for.

These boards are here for discussion and assistance to those needing help. Comments like these, for better or worse, turn new people away, stifle questions that others can learn from and ultimately reduce the interaction……

I feel like we have to self police and let each other know when it’s just too much. Frankly the links ss sent had very little useful information in them (yes I read them), and also represented a unidirectional viewpoint from home brewers who may or may not have any true credibility…. Ben’s post was useful, helpful and in a quick read was better than all three links combined. Because the answer directly targeted the question …

There are a lot of different opinions and processes in this hobby. For example, I never make a yeast starter. Feel it’s a bad idea. I have personally seen more problems from them than they are worth, yet I see over and over people saying “make a starter”…. It’s opinion, and that’s why we have a discussion. It’s not spoon feeding to ask people’s opinion….

[Bradster68]

No need for everyone to get butt hurt over a comment.

If that was directed to my comment, then no one is “butt hurt”, however IMO ss’s comment was uncalled for.

These boards are here for discussion and assistance to those needing help. Comments like these, for better or worse, turn new people away, stifle questions that others can learn from and ultimately reduce the interaction to a a bunch of curmudgeons who feel great about themselves……

I feel like we have to self police and let each other know when it’s just too much. Frankly the links ss sent had very little useful information in them (yes I read them), and also represented a unidirectional viewpoint from home brewers who may or may not have any true credibility…. Ben’s post was useful, helpful and in a quick read was better than all three links combined. Because the answer directly targeted the question …

It wasn't directed towards you personally but for all who feel the need to sweat the small stuff .
Your right on "one" account. Ben's advise to me anyways is of great value. I take it seriously just like a list of many others who I feel offer great advice.
And as far as new people turned away, who
fukin cares. This forum was built on knowledgeable people giving great advice ( even if it butt hurts some) and let face it.
THAT'S WHY YOUR HERE.

So lets face it,as far as policing things no one gave you a badge for it. Go patrol a parking lot.

So maybe you should take your nightgown off and start acting like man.
If not.....maybe fly some where, where they'll accept you for who you are. buddy

[Dougmatt]

So maybe you should take your nightgown off and start acting like man.

Nice…. So disrespect, bullying and name calling is your default…. Good to know.

[Bradster68]

So maybe you should take your nightgown off and start acting like man.

Nice…. So disrespect, bullying and name calling is your default…. Good to know.

Like I said buddy

[StillerBoy]

Steve, keep your mind open and learn to use your “tools”. You really don’t need spoonfeeding.

Unfortunately ss, it's the new world behavior, and it's all over the place..

People either do not want or don't know how to make decision for themselves any more.. so by putting it out there, they get validation by someone else making the decision..

Mars

[StillerBoy]

The rest I’ve got in my fruit press with some fiberglass window screen, and I’m squeezing out as much as I can. The plan is to let that settle, rack off the clear beer on top, and add it to the low wines for the spirit run.

What is your expectation of the yeast after they have been exposed the crazy environment you are proposing to expose them too..

It would be expected, after some time working with yeast, to treat them with a like more respect..

If you have researched, you would have recognized how important it is to handle yeast properly, more so than in their dry state..

Mars

[Bradster68]

Sorry Steve. I apologize for hijacking your thread and turning it into a debate over what people post.
I know as well as others you are on the path to success. And that is obvious by what other members have said about you and your post.
I just feel that there's no need to have animosity over post or suggestions or directions that members here give. We are all seeking out in the end the ability to produce a fine spirit.
We need need to take what each others say with a grain of salt,mull it over and decide for ourselves what we get out of the response.
Again I opologize for lashing out. Sorry
From one distiller to the next.

[Steve Broady]

Wow…
I really didn’t mean to stir up anything other than some yeast trub! I really appreciate the support, but in all honestly I feel it’s probably far easier to just let a comment go if you don’t like it. Personally, I didn’t take any offense. Maybe it was justified, maybe it was a misunderstanding, maybe it was just someone having a bad day. Lord knows I’m guilty of being a bit too snarky when I’m in a bad mood, and I sure hope people are willing and able to overlook it if the bulk of what I have to say is worthwhile.

Back on the main subject..
It’s unseasonably warm here, so I’m not sure I can cold crash the yeast outside. The carboy I collected in is just a bit too tall to fit in my fridge without rearranging, so it might take a couple days for things to settle on their own. When they do, I’ll see how it turns out.

[Bradster68]

Wow…
I really didn’t mean to stir up anything other than some yeast trub! I really appreciate the support, but in all honestly I feel it’s probably far easier to just let a comment go if you don’t like it. Personally, I didn’t take any offense. Maybe it was justified, maybe it was a misunderstanding, maybe it was just someone having a bad day. Lord knows I’m guilty of being a bit too snarky when I’m in a bad mood, and I sure hope people are willing and able to overlook it if the bulk of what I have to say is worthwhile.

Back on the main subject..
It’s unseasonably warm here, so I’m not sure I can cold crash the yeast outside. The carboy I collected in is just a bit too tall to fit in my fridge without rearranging, so it might take a couple days for things to settle on their own. When they do, I’ll see how it turns out.

You are absolutely right. I got caught up in the moment and should practice what I preach. Deep breaths and let it go.

But... it's an Interesting post and I'm intrigued enough (and who doesn't want to save some.money).
Especially when buying some of the more expensive yeast. If you can stretch them out a little. Awsome. I will be giving this a shot. I'll let ya know how I make out.

[Sporacle]

I don't think the importance of sterilisation for the yeast storage, separation vessels and utensils used should be underestimated either

[Steve Broady]

Just rereading this thread and the links, I realized that I forgot one salient point, and what seems like a significant departure from beer brewing techniques. I’ve been fermenting on the grain, and that’s not really much of a noticeable yeast cake on top of the grain bed. I assume the yeast are all throughout the grain, but that gets discarded after pressing. This is where the beer brewing stuff left me with a question: will I still have enough viable yeast in suspension after pressing to make harvesting worthwhile, or will I lose them all in the grain? My best understanding is that it’s practical, and that seems to have been confirmed. And as I said earlier, it’s easy to test.

My hope is that, in addition to saving a little money, over time I will end up with a collection of yeast strains that are unique to my environment and which work well for this recipe. If nothing else, it’ll add to my knowledge and experience as I progress in the hobby.

[Steve Broady]

Over night, it has settled quite a bit (what a difference from all my previous failed mashes!!!) and I see three distinct layers at the bottom. Again, just checking my understanding here. I’m encouraged to believe that the largest portion is live yeast because of the bubbles that I can see in it. And as always, I am quite prepared to be totally wrong.

[Ben]

You've got good settling there, but its mislabeled. The light layer in the middle (just below the beer) is live, healthy yeast.

The beer itself also contains live yeast, but its slow flocculating. If you are using a yeast blend this may be a difference in strain (especially if the blend has a Belgian strain in it) but if you have only one strain the bulk of what you want is concentrated in that thin, light colored layer. If you are using a single strain of yeast decanting that top layer while it's still cloudy is a good way to get rid of some mutated/unhealthy yeast and keep them from propagating further. If you are using a blend let it clear further.

The bottom layers are grain bits and dead yeast.

It might not seem like a lot of yeast, but there is really a ton in there.

You did a good job of pulling the yeast off the grain, I expected a lot more grain chunks in there. You can proceed to wash the yeast further, but for a slurry or starter you have what you need, just decant the layers out.

[Ben]

Any thoughts about how many generations you can harvest from or any concerns to be aware of harvesting yeast for use over and over?

Depends on your sanitization practices and how healthy your ferments are, and on your tastes. In the beer world they go 5-7 (until they start to notice off flavors, or flocculation gets bad). I find the best flavor from a strain comes in around the 3rd or 4th generation, then it starts to taper off a little. Distilling is less sensitive (especially if you don't mind some lacto/brett/pedio/whatever), I ran at least 20 generations of ferments on a packet of S04 blended to WLP099 over the last couple years, it never gave performance issues. But that isn't by accident... I adjust water minerality, have a good nutrient schedule and shoot for a starting gravity around 1.058, I pitch proper cell counts... I work hard to keep the yeast in good shape even if I do let it get funky from the environment.

I did find some really beautiful stuff (in the same recipe) in different batches at the still, but you have to let yourself be sensitive to the flavors and keep good notes. It's worth setting aside a little bit of the final white blend from each batch (if you are doing repeat recipes) to compare, it is a tangible way to track how your ferments are performing; it's hard to know what is going on based just on whether the ferment finishes dry or not. In a perfect world all of your white would taste the same, batch to batch. But between blending, fermentation, and human error there can be detectable changes. And the taste/nose will give you better info than any fancy piece of equipment.

If you start to notice a decline in the flavor toss the yeast and start over, or build a new starter from some yeast set aside from an early ferment: If you pull a sample of yeast from your first ferment and store it properly (washed yeast, in the freezer, under glycerin) you can pull a bit of that and build starters from it pretty much forever.

You see people on this forum who have been pitching the same cake of UJSSM for 10+ years. I think a lot of the UJSSM flavor comes from the infections and the wildly occurring yeast that is on the raw grain used in the recipe.

[Ben]

Yeast from an existing, healthy ferment, is never a bad idea, and too much is never bad either.

Dramatic overpitching yeast can cause a pH crash, lack of esterification and mutation of the strain. The right amount is the right amount, there is enough yeast in a cake for 5-10 future ferments.

[Steve Broady]

You've got good settling there, but it’s mislabeled. The light layer in the middle (just below the beer) is live, healthy yeast.

Thank you, this is exactly why I wanted to ask!

I’ve relabeled the image, mostly for the benefit of anyone coming along later. I hope the first version won’t be used as a reference, and that they see this one.

[still_stirrin]

The challenge will be the “harvesting” of the yeast. It’s hard to collect the top (light & fluffy) and omit the lower layer(s) which is settled proteins and yeast hulls. In a carboy, after racking off the beer, you will swirl the remains and pour it all into another container. Then, you let it settle there again for a few days. This time, you may be able to siphon the top layer of fluffy yeast. But it will be difficult.

In the brewery, the fermenters often have conical bottoms, which allow you to draw off the bottom off from the bottom of the beer. And the elimination of the settled protein matter and spent yeast is easy while you collect the healthy yeast through the valve.

Of note, for serious homebrewers, there are commercially available fermenters priced and sized for hobby use. If you’re serious enough about harvesting and re-use of the yeast, then I think it wise to investigate (and invest) in such a fermenter. Again, look to homebrewing suppliers and forums for a more extensive discussion of these tools.
ss

[StillerBoy]

n a carboy, after racking off the beer, you will swirl the remains and pour it all into another container. Then, you let it settle there again for a few days. This time, you may be able to siphon the top layer of fluffy yeast. But it will be difficult.

The difficult can be reduced by using different size containers..

Example.. went collecting trub, I will use a gal wide mouth jar and add some water, and after a day or so, decant the top part into a half gal wide mouth jar, and give it some time again, then decant into a narrow 1L jar to finish and decant into small jar saving jars..

Mars

[Ben]

Dropping the yeast into a smaller jar will help.

The easy answer (but requires a graduated cylinder) is to pour off most of the beer, then as much of the yeast as you can. Drop a sample of that yeast into a graduated cylinder, chill and read how much yeast you have in the cylinder:

Once you have that number you can use the yeast calculator I posted earlier to figure out how much of the slurry to pitch.

After you have done it a few times you will have a really good idea of how much you need and it will be quick.