UPDATE: Starsan Effectiveness in Brewing

Probably most folks on this forum are familiar with the lack of effectiveness from Starsan on certain microbes.  Bryan from Sui Generis, not GBF, has released his first video in a new series and it explains the “myth” of the lack of effectiveness as well as providing a digestible description of how starsan actually works on the microscopic level.  It’s very nice to see such an easy to understand description of how starsan works from someone who lives does this field of work for a living.

Blog post: Sui Generis Brewing: New Video...and a New Video Series

Direct Video: https://youtu.be/0JC9n50RdVo

It’s not microbes that are the issue with Star San, it’s yeast and mold.

Video says that contrary to myth Starsan kills yeast.  Video seems plausible to me.

This has been a topic of discussion on the MTF FB group. I emailed Five Star and got the response below.

“StarSan was tested and approved for Ecoli and Staph which are both gram-positive bacteria aka larger bacteria. So short answer no we haven’t officially tested for the kill rate on yeast bacteria and mold. However knowing that StarSan kills those two bacteria in an EPA good lab practice testing I would be confident in it’s effectiveness.”

They never tested, just assumed.

Video appears to be theoretical rather than based on actual kill data.  Again the theory is plausible, but it isn’t clear how much contact time is required.

Is there a difference in effectiveness between the various stages of the yeast lifecycle? In particular, can dormant yeast survive StarSan or some other santiation treatments? I’ve seen odd references (but can’t quickly track them down now) to different gram reactions for yeast in different stages, and I wonder if this is indicative of sanitizer resistance.

[quote]This has been a topic of discussion on the MTF FB group. I emailed Five Star and got the response below.

“StarSan was tested and approved for Ecoli and Staph which are both gram-positive bacteria aka larger bacteria. So short answer no we haven’t officially tested for the kill rate on yeast bacteria and mold. However knowing that StarSan kills those two bacteria in an EPA good lab practice testing I would be confident in it’s effectiveness.”

They never tested, just assumed.
[/quote]

Just wanted to point out that E. coli is a gram-negative bacteria and gram staining doesn’t refer to size of bacteria.  A bit pedantic I know and doesn’t change whether or not their product works, but Five Star reps should probably get that right given their line of products.

I use Stars an for yeast washing and the yeast works fine afterwards, so clearly it doesn’t kill yeast very effectively.

As was pointed out by Mark, a search on the Internet shows that many do this.

My own experience was that a couple kegs would go to Brett flavor and aroma after a while. Using Iodophor rather than SS to sanitize fixed that.

chlorine dioxide is a much better yeast washer - but starsan is a good sanitizer for anything preboil.  Post boil for me peroxidic acid/Peracetic and iodophor.  I don’t trust star san to clean my starter equip or my bottling equipment.

Very nice reference. Doubters should read the “Tried and True” section. It says acid washing is generally ineffective against wild yeast and mold.

So, I haven’t listened yet, but I think a couple of differences are

  1. Always clean before you sanitize.  An entire pitch of yeast is different than a few cells.

  2. Star San has other properties than just low pH for killing

Good information.  I’ve noticed as I’m sure others have that any leftover StarSan mixed with water and left in a bucket for a month or two will turn cloudy and might even have something “growing” in it after time, which has recently led to me switching back and forth now between StarSan and good old Clorox bleach for sanitization.  I figure between the two, the critters are dying somewhere in there.

Not to mention I use glass to ferment now instead of plastic, except for very small experimental batches where I’m not afraid to use gallon “milk” jugs for one-offs (I would not re-use these).

What are you sanitizing pre-boil for?

I sanitize my mash tun, my BIAB set up gets a starsan treatment, my utensils, my thermocouple, my chiller sits in starsan until about 10mins before end of boil.  That’s the only sanitizer I use on it before it gets put up.  I don’t use iodophors or peroxidic acid on my mash tun stuff or my utensils because they don’t really need it because they are only used preboil and utensils during boil.

They don’t need starsan before end of boil either. Do your thing, but it’s not doing anything for you.

Well I am not going to leave them unsanitary on the shelf, but I understand most just soap and rinse.  Which is fine, I just like to sanitize my stuff before they get put back on the shelf.  I guess that’s just me??  I know it is an extra step, but I like it.  I also burn alcohol in my boil kettle after I clean and rinse it, so idk, again just me, and then it gets a hit with starsan too before it gets put up.

I haven’t tried more than a couple of generations but I can imagine that things would go awry after a while due to wild yeast and mutations.

I’ve gone back to using Iodophor 90% of the time.

. Me too, I just had some very minor issues with Star San which could be operator error, but they cleared with Iodophor.  Also considering using boiling water or pressure cooker as a pre-treat on sour-exposed equipment to get where the chemicals might miss. Steam is impractical for me.