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General Category => Yeast and Fermentation => Topic started by: abraxas on October 19, 2010, 06:05:51 PM

Title: Dissimilar Yeast Flocculation
Post by: abraxas on October 19, 2010, 06:05:51 PM
If I brew a beer with a less flocculating yeast like German Ale, can I add a more flocculating yeast like Scottish Ale to speed up clearing of the beer?

It seems like in some situations it would be nice to have a a yeast cake which is less susceptible to being stirred up. 
Title: Re: Dissimilar Yeast Flocculation
Post by: euge on October 19, 2010, 06:09:41 PM
That's a good question. My instinct says no. But no experience so maybe it will?

You'll probably need a fining agent.
Title: Re: Dissimilar Yeast Flocculation
Post by: denny on October 19, 2010, 06:39:12 PM
I don't think it would work.  Why would a more flocculant yeast "pull down" a less flocculant one?  Thigs like Irish moss work because they have an opposite electrical charge.  That wouldn't be the case with 2 yeasts.  But I'm guessing....
Title: Re: Dissimilar Yeast Flocculation
Post by: tschmidlin on October 19, 2010, 06:58:20 PM
That's an interesting question - my answer is "maybe".

Strains flocculate because they express proteins/glycoproteins on their cell surface that allow them to clump together.  The larger clumps fall out of solution faster.  Low floccing strains have less of the proteins than high floccing strains.  So hypothetically, since the high floccing strain has more places to "grab on" to it's possible a high floccing strain could stick to some of the low floccing strain and help it settle out faster.

It's worth an experiment I think :)
Title: Re: Dissimilar Yeast Flocculation
Post by: denny on October 19, 2010, 07:02:06 PM
Believe Tom, not me!
Title: Re: Dissimilar Yeast Flocculation
Post by: Joe Sr. on October 19, 2010, 09:05:02 PM
If all you're trying to do is clear the beer, a fining agent, as Euge suggests, such as knox gelatin would be a lot cheaper than another batch of yeast.

Title: Re: Dissimilar Yeast Flocculation
Post by: abraxas on October 19, 2010, 10:23:45 PM
If all you're trying to do is clear the beer, a fining agent, as Euge suggests, such as knox gelatin would be a lot cheaper than another batch of yeast.

Yes, but sometimes timing just works out right.  Right now I have a Saison that has been finished for a while; whenever I move it the bottom 3 or 4 inches become really cloudy and take a long time to settle.  When I rack it I expect I will get a lot of that yeast entrained.   I know I could add a fining agent but since I will have some Scottish Ale yeast from a different fermentation that I will otherwise dump I was thinking maybe I could add this to compact the yeast cake (sort of)...  Might be a good use for the early floccing yeast from a conical if you could clean it...

When I transfer these beers I'll separate the Saison yeast into two equal jars and add some Scottish to one of them, this should be a good way to have a preliminary test.... 

I'm always worries about fining agents stripping too much character from the beer.  I know I just need to compensate the recipe but I don't have a solid foundation of house recipes the experiment around with like that yet.
Title: Re: Dissimilar Yeast Flocculation
Post by: Joe Sr. on October 19, 2010, 11:46:52 PM
In that case, it certainly doesn't hurt to try.
Title: Re: Dissimilar Yeast Flocculation
Post by: wingnut on October 29, 2010, 03:32:30 PM
Useing two yeasts for flocculation purposes will work...if you are lucky.  It may take a few tries to get the timing and quantities down.  However, when this does work, the resulting beer will have characteristics of both yeasts. 

Essentially, if you pitch two yeasts at the start of fermentation, the two kinds of yeast are in competition with eachother.  As long as they are both beer yeasts, they can exist nicely.  (Note, if you add wine yeast and beer yeast, most wine yeasts will kill off the beer yeast!!!)  However, the two kinds of yeast are in competition with each other to take over the carboy.   Some yeasts are sprinters and take of quickly, others marathon runners and start slow, but just keep chugging.   If you have a sprinter yeast and a marathon yeast, the sprinter will multiply fast than the marathon yeast.... so you when it comes time to active fermenation, instead of a 50/50 yeast population, you may have 80% sprinters and 20% marathon runners. 

Depending on which one makes the better beer, and which one provides the flocculation, the 80/20 mixture may be exactly what you want. 

Be advised, however, if you are re-pitching from the yeast cake, you are starting with a 80/20 mixture of the yeast, and the same sprinter/marathon issue will cause you to have say...90/10 ratio in the next beer...etc


With some experimentation, I have come up with a WLP830/001 mixture that gives a real nice ALT characteristic.  What I do is pitch a vial of WLP830 into the wort at 58F, let the wort rise to 62F over 12 hours and then add a vial of 001.  The head start of the lager gives it enough population to compete with the 001, the 001 gives a nice ale quality to the beer, and the lager yeast, finishes the beer over the next 8 weeks lagering very nicely.   What I am after is the finishing properties of the yeast instead of the flocculation, but I expect the same factors apply.

Enjoy the fun, and I hope you make a ton of great beers while perfecting your technique!