Can starsan kill yeast?

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chris246810

Can starsan kill yeast?

Post by chris246810 » Mon Sep 12, 2016 8:04 am

I recently attended my first meeting with the midlands craft brewers group where one of the more experienced members did a talk where he mentioned that he doesn't entirely trust starsan as a no rinse sanitiser due to something he read in a book by Dave Miller (see attached image)
He said he always rinses off any residue after sanitising, and uses a slightly stronger than recommended solution with the addition of a small amount of phosphoric acid to increase the storage life of the solution.
I've done a fair bit of searching online to try and back up or disqualify what he said but can't seem to find the details I'm looking for.
I've always used dried yeast in my brewing, haven't yet got to the stage where I've tried experimenting with the use and storage or liquid yeasts, as far as I understand when using starsan as a no rinse, the sheer volume of liquid quickly dilutes and starts to break down any starsan residue so it can't kill anything good or bad in the wort.
But maybe this isn't the case when using a sanitised container for storing a small amount of liquid yeast.
Has anybody carried out any experiments using starsan non rinsed and rinsed to see if there is any difference in yest cell counts?
2016-09-12 08.05.58.jpg

AnthonyUK

Re: Can starsan kill yeast?

Post by AnthonyUK » Mon Sep 12, 2016 8:42 am

I leave it in empty FVs and other containers for months and nothing grows in them.
This appears to be another 'black catter' who tries to go even further.

As long as its pH remains below 3-3.5 it will work.
Out of interest what does this person use to rinse? :?

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Re: Can starsan kill yeast?

Post by Jocky » Mon Sep 12, 2016 9:02 am

It's an acid. It kills or retards the growth of bacteria primarily by lowering the pH, although wort will return the pH to the expected level which is safe for yeast.

To me, this book anecdote is one data point in an otherwise sea of data that backs up StarSan as being a very good product. So I think you have it about right - use starsan where you're going to massively dilute it with wort.

As a side note, StarSan is not very effective against fungal microbes - wild yeast, mould - so you shouldn't trust it 100% to make up for sloppy cleaning/sanitisation practices.
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.

chris246810

Re: Can starsan kill yeast?

Post by chris246810 » Mon Sep 12, 2016 9:34 am

He uses tesco Ashbeck for making up starsan solution and his very hard tap water for final rinsing.
In my opinion, there's a much higher chance of introducing bad bacteria from the tap water than the chances of anything bad happening from leaving starsan residue in the vessel.

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Jocky
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Re: Can starsan kill yeast?

Post by Jocky » Mon Sep 12, 2016 10:01 am

chris246810 wrote:He uses tesco Ashbeck for making up starsan solution and his very hard tap water for final rinsing.
In my opinion, there's a much higher chance of introducing bad bacteria from the tap water than the chances of anything bad happening from leaving starsan residue in the vessel.
I agree.

The other negatives in the book excerpt above are from using hard water with starsan. If it goes cloudy then the solution won't keep and will eventually end up leaving soapy deposits as described, but with soft water like Ashbeck it's fine for a long time.
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.

chris246810

Re: Can starsan kill yeast?

Post by chris246810 » Mon Sep 12, 2016 10:19 am

I suspect the 'friend of a friend told me' type anecdote in that book is misleading, mainly because I've failed to find a shred of evidence to support the claim.
Now to find someone with a decent microscope to lend me so I can do some tests to prove it one way or the other.

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Re: Can starsan kill yeast?

Post by Jocky » Mon Sep 12, 2016 10:24 am

chris246810 wrote:I suspect the 'friend of a friend told me' type anecdote in that book is misleading, mainly because I've failed to find a shred of evidence to support the claim.
Now to find someone with a decent microscope to lend me so I can do some tests to prove it one way or the other.
Homebrewing on the internet is very much 'Question Everything' at this point, so I'd be really surprised if nobody had piped up that Starsan was a yeast murderer by now.
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.

AnthonyUK

Re: Can starsan kill yeast?

Post by AnthonyUK » Mon Sep 12, 2016 10:31 am

BTW - I've noticed Ashbeck has changed in the past year or so and now goes slightly cloudy but still remains withing the required pH range even over an extended period.
Jocky wrote:Homebrewing on the internet is very much 'Question Everything' at this point, so I'd be really surprised if nobody had piped up that Starsan was a yeast murderer by now.
In small doses isn't it meant to be beneficial to yeast?

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Re: Can starsan kill yeast?

Post by Aleman » Mon Sep 12, 2016 10:45 am

Actually, Star San is very effective against bacteria, but due to it's nature and method of action is less effective against molds and fungi. . . . And yeast is a fungi ;)

Does that stop me using it? No. Does that stop me using it no rinse? . . . No. Would I use it for sanitising a flask for yeast work, starter prep ect . . . . Hell NO!

As long as the 'vessel' has been thoroughly cleaned, then starsan works fine . . . but I do alternate between starsan no rinse and iodophor no rinse, and occasionally hypochlorous and peracetic acids (Which are also no rinse).

I don't think the 'perfect' one solution answer to sanitising exists, but a combination of appropriate products will do the job well.

chris246810

Re: Can starsan kill yeast?

Post by chris246810 » Mon Sep 12, 2016 10:58 am

Ok, so for fermenting bins and other brew equipment starSan can be used without any issue as a no-rinse solution.
Would it be better to use a different sanitiser or still use starsan and just rinse off the residue when making a yeast starter?

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Re: Can starsan kill yeast?

Post by Aleman » Mon Sep 12, 2016 11:01 am

I use an autoclave for yeast work, including starter preparation. I don't trust any, readily available, chemical methods to fully sterilise sufficient for yeast work. . . . and star san is not that effective against wild yeast

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Re: Can starsan kill yeast?

Post by Matt in Birdham » Mon Sep 12, 2016 11:10 am

chris246810 wrote:Ok, so for fermenting bins and other brew equipment starSan can be used without any issue as a no-rinse solution.
Would it be better to use a different sanitiser or still use starsan and just rinse off the residue when making a yeast starter?
There does seem to be quite a bit of debate on the blogosphere about whether or not Starsan is an effective fungicide - mostly from a few people who say that acid based sanitisers can never be effective against yeast. I'm not qualified to comment, but it is worth noting that Starsan advertises itself as a "Broad Spectrum Bactericide and Fungicide" and has USDA approval as such for use in the US dairy industry - which I suspect is at least as demanding an environment as brewing. Anecdotally, I've had one confirmed wild yeast infection in my brewing career, which I traced back to an uncleaned, unsanitised and disgusting ball-valve - which makes me think that Starsan is doing a decent job the rest of the time.

I've had no issues using no-rinse starsan in starter flasks and FVs - even if we accept that fact that Starsan does kill yeast effectively, it would only ever do so on the surfaces it is applied to (the same for bacteria) - as soon as it is diluted with wort then the power is gone.

Having said all that, I also mix up my sanitising regime and use iodophor every now and then - I think that is just good practice.

McMullan

Re: Can starsan kill yeast?

Post by McMullan » Mon Sep 12, 2016 11:30 am

+1 for iodophor. If using on plastics, a weaker solution (12.5 ppm) and contact time of 5min doesn’t cause staining. It is unlikely Starsan is going to be noted as not working, because brewers yeast should have a very big advantage, numerically, and is more likely to mask any wild yeast character.

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Re: Can starsan kill yeast?

Post by rpt » Wed Sep 14, 2016 5:36 pm

So the author is using a single incident of third hand information to cloud his judgement.
Last edited by rpt on Wed Sep 14, 2016 11:19 pm, edited 1 time in total.

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Re: Can starsan kill yeast?

Post by Jocky » Wed Sep 14, 2016 8:32 pm

+2 to iodophor here, although once dried I use starsan as a final rinse too

Not so bothered about the staining - if it's red, it's dead!
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.

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