Star San Sanitizing But Not Killing Yeast?

[Joshua542]

This is one thing I've always wondered. If Star San is a no rinse sanitizer how does it sanitize and kill bacteria and not the yeast? The guy at by local beer store said I don't even have to let it dry, I can put the beer in the bottle or fermentor right away after I dump out the Star San? What do u think? But If I let it fully air dry out in the open for an hour or more then it has potential to be re-expoised to bacteria in the air.

And what about all the foam with star san? I end up getting tons of foam in my 12 ounce bottles?

 

[Hammy71]

Don't fear the foam. In fact Star San is pretty much useless if you let the surfaces dry. It's effect on yeast? Some contend it actually has elements that are needed for yeast growth. It's a 'no rinse' sanitizer that lowers the ph so low it kills bacteria. No worries.

 

[wonderbread23]

As soon as you pour beer into a vessel coated with beer, it is diluted to the point that it won't affect the yeast. If there is bacteria in the liquid you're filling a vessel with, it won't kill it either.

I let as much foam drip out as possible, but don't think twice about filling on top of it.

 

[Captain Damage]

It's a pH based sanitizer, meaning that it only kills when it's concentration causes the pH to be 3 or lower. When you fill your bottles with beer, it dilutes the Star San so the pH is no longer low enough to kill. In fact, at low concentrations the yeast is able to utilize the phosphorus as a nutrient.

 

[kh54s10]

I don't know the true chemistry that makes it work but I love it. I use a vinator to sanitize my bottles and put them on my dishwasher rack to drain. The bottles do not totally dry and are upside down so any nasties don't get in. There is just enough Starsan foam to act as an indicator that the bottle is full.