Star-San and Yeast

[JeffD1]

I have had one nagging question in the back of my mind for months now. Star San kills most living things...including wild yeast (at least I'm fairly certain of this). Yet, it is absolutely fine if it gets into the beer and it does not seem to affect brewers yeast. Can anyone offer an explanation of this? Does star-san not kill yeast (wild or brewers), or is wild yeast genetically different enough to be affected by star-san?

 

[TyTanium]

Dilution. It kills via pH. When residual StarSan foam dissolves in beer, it's far less concentrated, the pH rises, and it no longer kills.

 

[Hello]

Dilution. It kills via pH. When residual StarSan foam dissolves in beer, it's far less concentrated, the pH rises, and it no longer kills.

This. Last night I racked into a carboy for the first time. When I realized that sloshing around StarSan in the carboy created foam, I didn't know what to do. Knowing that by rinsing it would essentially make the whole StarSan efforts pointless, I read (probably from Revvy) that we shouldn't fear the foam and in fact, it will be pushed out by the wort probably. He wasn't wrong. Further reading explained the dilution was key. Now, if you stuck an ounce of undiluted StarSan in your bucket and filled it with wort then I would assume you would cause a negative reaction to the yeast.

 

[JeffD1]

Dilution. It kills via pH. When residual StarSan foam dissolves in beer, it's far less concentrated, the pH rises, and it no longer kills.

Ah! Of course, makes sense. Thanks a lot!

 

[WoodlandBrew]

Star San can actually be used to preform real yeast washing similar to how the pro's do it. Details in my book, but you can see a preview on my blog.

http://woodlandbrew.blogspot.com/2013/03/acid-washing.html
(Note: I have refined the procedure after this blog post)

 

[wefdog]

I have had one nagging question in the back of my mind for months now. Star San kills most living things...including wild yeast (at least I'm fairly certain of this). Yet, it is absolutely fine if it gets into the beer and it does not seem to affect brewers yeast. Can anyone offer an explanation of this? Does star-san not kill yeast (wild or brewers), or is wild yeast genetically different enough to be affected by star-san?

Perhaps brewing yeast is a bit more sturdy but I think it would still die in my opinion otherwise you would have to buy new stuff each brew day. That is your champagne yeast leftovers would contaminate and make your beer or wine go further than an ale or regular wine yeast.

 

[cluckk]

Star San can actually be used to preform real yeast washing similar to how the pro's do it. Details in my book, but you can see a preview on my blog.

http://woodlandbrew.blogspot.com/2013/03/acid-washing.html
(Note: I have refined the procedure after this blog post)

Thanks Woodland, I can't wait to try this.

 

[JLem]

.... That is your champagne yeast leftovers would contaminate and make your beer or wine go further than an ale or regular wine yeast.

champagne yeast does not really ferment "more" than ale yeast or other wine yeasts. Champagne yeast are highly tolerant of harsh conditions like high ABV, low oxygen, low pH, etc...which is why it can be used to make high ABV wines and meads, and is useful to add when bottling big beers.

In general, using champagne yeast in beer will not leave you with wine-like final gravities...because beer wort contains more complex sugars than wine must, which cannot be fermented. In addition to the yeast species and strain, you also need to consider the makeup of what is being fermented. Pretty much ANY yeast will take apple juice below 1.000, even ale yeast. And pretty much NO yeast will take beer wort that low.