Mixing Yeast?

What are people’s experiences with mixing yeast strains. I made a simple dry stout last year from Wyeast Irish Ale yeast but didn’t get the full attenuation I wanted. I read (somewhere - BYO mag?) that Irish Ale yeast attenuates poorly in lower OG beers. Anyway my plan this year was to throw in one packet o’ Irish yeast and one packet o’ American 1056. Will I get a more fruity Irish ale taste but with a fuller attenuation, will the yeasts compete and one will just win out or will the this reality collide with another?

Probably one will dominate the other.  It’s pretty much unpredictable and unrepeatable.

If you throw in one packet of each there will be a lot of yeast in there.  I doubt one would truly dominate, but it might be 55/45 or 60/40.  I agree with Denny, it may be largely unpredictable, but it should be repeatable.  You’ll need to account for the health of the yeast pitched though - if one time it is 1 week old 1056 and 2 month old 1084, and another time it’s 1 week old 1084 and 2 month old 1056, you will probably get very different results.

I would recommend fermenting with 1084 - if you didn’t get the attenuation you want last time, mash lower this time.

Alright sounds like an experiment then. Maybe I’ll try to get yeast dates that are close to each other.

Sometimes mixing works and you get the best of both worlds.  Sometime not so much.  I would read up on both yeasts and try to give one a head start if you wanted it to dominate.  So  if one starts faster than the other, pitch both at the same time in the same condition.  If they take off about the same, try pitching one at high kroysen, and the other from a dormant state.  The high kroysen should  take off faster… you could also try pitching one, and then pitching the other 12 hours later.

While I agree with Denny that the results may be somewhat unpredictable, the few times I have tried it, the results were fairly similar.  I suspect from a spectrometer standpoint, the results are different, but from a flavor threshold standpoint, they came out very similar.  (I did not like the belgian, american ale yeast results…but they were repeatable).

Good luck, try it, you may find a magic mixture!

And then there’s the split batch method. You can then blend the results in whatever proportions to get the best of both strains.

I did this recently with a 10 gallons batch of Weizen, split between two German Wheat strains and then blended into a keg.  I reused the combined yeast on the next batch, but I think I prefer the single strain (not Weihenstephan, the other one).  It was an interesting trial.

I have done this numerous times over the past 16 years with excellent results.  Yes, it may be unpredictable, but isn’t most home brewing that way?

Definitely try it and remake the same batch so see if there is a difference.  From my experiences the outcome has been fairly predictable, but I stick with yeast strains that are close in profile.

I try to avoid unpredictable in my homebrewing.  Not that it doesn’t sometimes happen, but that doesn’t mean I have to like or accept it.  YMMV.

Unfortunately for us, at our level there are many unknowns and things we can’t control.  But that’s what makes it fun!  If home brewing were like making shake-n-bake pork chops (mmmmmm…), it wouldn’t be that fun anymore.

plus one…

I’ve had success mixing yeast once, I used WLP007 with WLP041 and was pleased with the results in the long run

Just tapped a Saison fermented with a blend of White Labs 550, 565, and 570. It’s dry, fruity, and spicy; couldn’t be happier with the outcome.

In White’s+Zainasheff’s book “Yeast,” Chris White talks about how he’s helped different pro breweries come up with yeast mixes to achieve specific goals, like better attenuation in high gravity beers, or more complex flavors, etc.

The interesting thing he said was that the growth curves for beer yeast are all pretty much the same, so it’s unlikely and rare that one yeast will dominate upon the first pitch. He does mention that over subsequent generations, the slurry population will drift, but he said that even with a 90/10 split, the beer had the same desired traits from the mixed culture as the beer did on first pitch.

So, there’s that. I can’t personally verify that, but I’d bet Chris White knows a thing or two about yeast.

I’d agree that Chris White knows something about yeast!

Not that I have any evidence one way or the other, but I’m curious to know where the notion developed that one yeast would dominate the other in mixed pitches. . .

Another issue White brings up when using mixed cultures of “regular” (non-Brett) brewer’s yeast. Most of the yeast flavor will form within the first 72 hours of fermentation. So if your only goal is to increase attenuation, you should pitch the more attenuative yeast after a few days to allow your primary yeast to make the flavor profile. If you want both yeasts to contribute to the flavor, then pitch them both at the same time, or within that 72 hour window, if you want less flavor from one.