Could killer yeast affect my sourdough starter?

Question

Could killer yeast affect my sourdough starter?

aucuparia

2019年3月5日 09:47

I've just pitched K1-V116 into a batch of rosehip wine. As I finished, thoughts of one kind of yeast led to another and I went to feed my sourdough starter - and stopped. K1-V1116 is a killer strain which secretes toxic polypeptides able to kill other strains and species.

I have heard that even minute levels of yeast contamination (such as from having previously made a sourdough in the same room - even many months previously) can completely prevent establishing ginger beer plant.

Does anyone have any experience or information on how likely I am to have problems with tiny amounts of leftover K1-V1116 killing my sourdough starter? There is bound to have been a few thousand cells lofted into the air when I opened the packet. How paranoid about this do I need to be?! I make wine and bread in the same kitchen and I like my established sourdough starter!

Topic wild-yeast yeast homebrew

Category Mac

aucuparia · Accepted Answer · 2019年3月5日 09:47

Well, I've been using the starter and have not had any problems. Certainly K1-V116 hasn't completely destroyed the sourdough starter - it's still sour so there must be lactobacilli still alive!

It does seem more active than usual so it's possible that the wild yeasts have been replaced by K1-V116, but the effect is not very marked.

Update 6 months on: there is a noticeable difference in the starter. On the plus side, it's less fussy with regards to temperature, proves faster, and gives a better texture. On the minus side, the flavour is much less complex - less sourdough and more normal yeast.

Whether this is down to the wine yeast or some other factor I will never know, but I would recommend caution when using killer yeast around starter cultures.

Dave · Accepted Answer · 2018年10月22日 14:23

In principle, yes, in the sense that any rogue outside yeast or bacteria could take over your sourdough. However, in what you described, I wouldn't worry about potential cells that have become airborne. They would not only have to find their way to your starter, but then take hold and out compete what you've got going in your starter.

By the way, if you are happy with your starter as it is, you might want to consider freezing some of it. Starters, by virtue of being alive, evolve on their own or from what they pick up in its surroundings. Think of it as creating a backup copy of your starter.

Could killer yeast affect my sourdough starter?

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