Blending yeasts

Iliff Avenue Brewhouse

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Can someone explain to me the challenges of blending yeasts? I've been wanting to pitch a packet of S-189 and M76 into a lager. Would the results not be repeatable? Others have advised against it saying that the results will be inconsistent from batch to batch.
 
If you're pitching the same yeasts in the same ratios on the same schedules with decent temp control I don't see why it would be any more inconsistent than pitching a single yeast. There's sure to be inconsistency due to the yeast at some level, but that's just yeast manufacture/capture. And would be there in a single strain approach as well.

I've done batches with mixes of yeasts (multiple sacchs and sach and brett) and mixes of yeasts and microbes. I haven't noticed any more variability repeating those than the single strain batches that I've repeated (i.e. it's down to my skill as brewer more than something inherent in mixing yeast).
 
It's hard to say which yeast will dominate. People who blend yeast find that eventually one strain takes over, so instead of having a 50/50 blend it tends to be 75/25 and eventually if repitched, it will be 95/5. I believe White Labs addressed this a while ago and found similar results.

I have blended yeast before, but I have come to the conclusion that it's better to ferment them separately and blend the beer instead the yeast. But it certainly won't hurt anything and the beer will turn out fine, but it may not showcase both yeast characteristics, one will dominate.
 
Blending lager yeasts may be a little futile since, ideally, you'd lager out all the yeast flavors and be left with a "clean" malty beer. Of course, in the real world, there's always some flavor contribution, even from lager yeasts. I'd say that if all went well, you wouldn't notice a big difference between the beers fermented with either of these yeasts and one with a blended yeast, at least not after lagering had cleaned things up.
That being said, I pitched 2 different yeasts on a lager to build up slurry for a couple of different brews. When it came time to a big batch, I decided that it had been sitting too long and neither pitch alone would be a high enough cell count. I ended up pitching all the slurry from both yeasts - S-23 and 34/70. Early on there had been a difference in the beers but it didn't take long for them to become more or less indistinguishable. Now with the blend, it just tastes like a young lager that's not cleared, but even before the yeast is dropped, it's tasting less fruity than the early samples of the starter batches.
I think cell count in the pitch will probably have a bigger impact on flavor and attenuation than pitching relatively similar strains.
 
Blending lager yeasts may be a little futile since, ideally, you'd lager out all the yeast flavors and be left with a "clean" malty beer. Of course, in the real world, there's always some flavor contribution, even from lager yeasts. I'd say that if all went well, you wouldn't notice a big difference between the beers fermented with either of these yeasts and one with a blended yeast, at least not after lagering had cleaned things up.
That being said, I pitched 2 different yeasts on a lager to build up slurry for a couple of different brews. When it came time to a big batch, I decided that it had been sitting too long and neither pitch alone would be a high enough cell count. I ended up pitching all the slurry from both yeasts - S-23 and 34/70. Early on there had been a difference in the beers but it didn't take long for them to become more or less indistinguishable. Now with the blend, it just tastes like a young lager that's not cleared, but even before the yeast is dropped, it's tasting less fruity than the early samples of the starter batches.
I think cell count in the pitch will probably have a bigger impact on flavor and attenuation than pitching relatively similar strains.

Thanks for the comment. I knew it would be a long shot but I was hoping gain a little bit of what I like about each strain. M76 is really good at accentuating malt but doesn't attenuate as much as I like. S-189 is just a great all around yeast for my purposes and love the amount of attenuation I get from it. At the end of the day I pitch two packets for lagers anyway so it can't hurt to give it a try with one of each and see what happens.

I'm more interested in making a house ale blend but haven't decided on two candidates yet...
 
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Thanks for the comment. I knew it would be a long shot but I was hoping gain a little bit of what I like about each strain. M76 is really good at accentuating malt but doesn't attenuate as much as I like. S-189 is just a great all around yeast for my purposes and love the amount of attenuation I get from it. At the end of the day I pitch two packets for lagers anyway so it can't hurt to give it a try with one of each and see what happens.

I'm more interested in making a house ale blend but haven't decided on two candidates yet...
A "house ale blend" won't survive multiple generations. One of the yeasts will outcompete the others and you'll wind up with essentially a monoculture again.
 
White labs and others sell yeast blends. So I don't know if the one strain out competes the other argument is correct. I haven't tried 're using their blends though, so I can't say for sure that subsequent brews get less mix of one. But I've seen other posts on mixing yeasts where people have argued that even the first batch with a blend will be all of one since it out competes the other, and that is definitely wrong.
 
White labs and others sell yeast blends. So I don't know if the one strain out competes the other argument is correct. I haven't tried 're using their blends though, so I can't say for sure that subsequent brews get less mix of one. But I've seen other posts on mixing yeasts where people have argued that even the first batch with a blend will be all of one since it out competes the other, and that is definitely wrong.
My guess would be they grow the two strains in different tanks, then mix them. Agree on the first batch, that simply can't be. And it might be a few generations before one strain outcompetes the other, then likely not completely - biology just doesn't work that way.
 
So how many generations are we talking about as far as one strain becoming dominant? I normally don’t go more than 3 generations...
 
So how many generations are we talking about as far as one strain becoming dominant? I normally don’t go more than 3 generations...
My guess is it will happen in the first fermentation. Without a lab to do a yeast count based on strain, there’s no way of know what the yeast count is for each strain.
 
Sounds like I will have to give it a try and expect to be disappointed. Thanks all. Much better than other forum responses.
 
My guess is it will happen in the first fermentation. Without a lab to do a yeast count based on strain, there’s no way of know what the yeast count is for each strain.
It will start at least. I don't know how many generations it would take for one strain to become dominant, depends on both yeasts and whatever competition factor is in play.
 
I have made beer with two strains pitched together before.
I have done Belgians where I added Brett to finish after the main strain was finished.
But, I have a thought in my head, so I'm going to do an experiment. Thoughts would be appreciated, and I will post back with the results.
I have two very different strains and have a simple 5% Blonde Ale I'm going to try to brew with them, hopefully getting certain characteristics from them. First yeast is S-33 to try and get some of the fruity character out of. Second yeast is K-97 mainly being used to help attenuate the finished product more. So, with that I'll be fermenting at around 65° and I will be pitching the S-33 first, hopefully developing that flavor. I am then planning to pitch the K-97 early on after fermentation has really started. One of my thoughts in this is that if I pitch the K-97 at the same time it might just end up being the dominant strain as I have had S-33 take a bit of extra time to take off. Also, if I pitch the K-97 too late, will the alcoholic environment be problematic for the yeast to really get started on it's own.
 

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