yeast competitive factors

[JLem]

A couple of questions regarding yeast competitive/killer factor. I know this doesn't apply to yeast usually used in beer (as none of them are "killers"), but after listening to an archived podcast on the BN (the one with Shea Comfort), I am interested in using some wine yeasts for some beers. I originally posted these questions in the wine forum, the only response I got was to try this forum. Maybe someone here can help?

1) What happens when two (or more) killer yeast are used together? Are they intrinsically immune? will they kill each other off? will one out-compete the other(s)?

2) How is Brettanomyces affected by kill factors? Are they susceptible? What about bacteria like Pediococcus and Lactobacillus?

 

[COLObrewer]

I know nothing about this and have heard even less, just my 2 cents. Hope this helps

 

[Shish]

Sorry to hop on an old thread, but I'm curious about something along these lines as well. I'm interested in taking unpasteurized and unfiltered cider and adding yeast without any pasteurization or chemical additives. I'm not sure how practical this is or if there is a particular strain of yeast that would be best suited for an attempt. Again, this isn't something I'm attempting yet. I'm just curious if it's possible or just a disaster waiting to happen.

 

[eritain]

Science knows at least 6 killer factors in S. cerevisiae, but as far as I can learn, at most 3 of them are expressed by commercially available wine yeasts: K1, K2, and K28.

A yeast that secretes a killer factor (or competitive factor, or zymocin ... terminology is really unsettled here) is also immune to it, so 2 strains that secrete the same one are presumably back to competing on other grounds -- speed of reproduction, tolerance for alcohol. But 2 strains that secrete different killer factors are both going to have a rough time of it.

K1, K2, and K28 only kill within the Saccharomyces genus. Klus kills in some other yeast genera. None of them kill Brettanomyces.

 

[eritain]

<clumsy double-post, sorry>

 

[BrewerofBeers]

And for the reasons you mentioned, one will almost always win out. How long that takes to happen also depends on these factors. So if you mix two strains, it's not like you have an indefinite ratio.

 

[BrewnWKopperKat]

Science knows at least 6 killer factors in S. cerevisiae, but as far as I can learn, at most 3 of them are expressed by commercially available wine yeasts: K1, K2, and K28.

Do any of those kill factors show up in yeast intended for bottle conditioning beer?

 

[day_trippr]

Pretty sure CBC-1 is a killer strain...

 

[BrewnWKopperKat]

Pretty sure CBC-1 is a killer strain...

agreed. Just curious if @eritain can mention which specific kill factors are in each strain of bottle conditioning yeast?

 

[MaxStout]

If you use wine yeast for bottling, some of those are kill factor. D-47, 1116, 1118, are a few that come to mind.
Milk the Funk goes into this in some detail, with some links to external sources.

Edit: A list of killer wine yeast strains, compiled by @Northern_Brewer.

 

[Kickass]

https://pricklycider.com/2020/12/19/yeast-killer-factor/

I saved this awhile back. Might be useful to the conversation.