# Yeast under starsan



## Yob (16/4/17)

weird thing right.. I was fermenting a RIS...

anyway, after the initial cleanup





I set to a rapid blowoff..





was holding sterile water so emptied it and put 500ml of starsan, that yeast was under starsan overnight till I just rinsed it with sterile water..

Im not %100 on the effect of the yeast under those conditions... anyone?


----------



## Markbeer (17/4/17)

For clarification the star San was in the milk bottle at the end of the blow off tube? It got sucked back?


----------



## Yob (17/4/17)

In the milk bottle yes, no it didn't get pulled back to the FV, I'd not be at all concerned about that, I'm curious about the yeast collected in the milk bottle from blowing off. There was quite a bit of yeast solid in the bottom.


Ultimately, I swapped that bottle out for a 3Lt with sterile water, so I can collect and save that yeast, I just don't know what effect starsan has on yeast neat..


----------



## technobabble66 (17/4/17)

So basically wondering if the starsan has killed it, as it's meant to be a sterilizing agent, or if it's niftily contained clean yeast under a sterile barrier, given yeast can be "acid washed" to clean out crud/dead cells and kill other infective microbes. 
I too have wondered about this - great minds, hey! [emoji6] However, I've never bothered to investigate or test further. 

Fwiw, I'm inclined to think the starsan will/should kill off the yeast. For 2 reasons: 
1) Because it's designed to be a universal sterilizing agent
2) we'd have serious issues with cross contamination of yeast strains (I'm looking at you, Belgian yeasts!) if it didn't kill off yeast as well. 

Without doing some reading, I'd guess the acid used in the yeast acid wash is a more chemically neutral or mild strength molecule (ie: a weak proton donor), whereas the phosphoric acid that I think makes up the starsan is a very very strong proton donor (I believe) so it will gradually attack everything that's susceptible to chemical attack. 

Definitely worth a quick little experiment to test this though [emoji41]

One thought: given the starsan would gradually be consumed by it's sterilizing action (normally it's in such vast "numerical" excess this isn't relevant to our regular use), I wonder if you used sterile water with a tiny bit of starsan in it, whether you'd have a mild sanitizing action (initially at least), that gradually accumulates the yeast within. 
No major step forward but it helps ensure your sterile/distiller water is that little bit more sterile.


----------



## DJ_L3ThAL (17/4/17)

technobabble66 said:


> Fwiw, I'm inclined to think the starsan will/should kill off the yeast. For 2 reasons:
> 1) Because it's designed to be a universal sterilizing agent
> 2) we'd have serious issues with cross contamination of yeast strains (I'm looking at you, Belgian yeasts!) if it didn't kill off yeast as well.


I've also been pondering this!

1) If Starsan did kill yeast, I would have had MANY a batch that wouldn't fire off. As for my rough and ready brews for camping we tip the cube into a sanitised fermenter which brings a lot of the Starsan foam to the top. We then sprinkle dry yeast onto this foam. No lag times, no noticeable reduction in yeast performance/growth etc. Same actually goes with my regular brews however liquid yeast cuts through the foam and gets straight into the wort.

2) The hot water or boiling temp PBW solution for cleaning I would think gets rid of most of the yeast. Starsan comes in after so not sure if people just "wash" their FVs etc with Starsan only. So think that debunks surety Starsan kills yeast.

Finally the "don't fear the foam" adage may add more to the argument Starsan won't kill yeast. I'm interested in the weak versus strong acid solution points though and whether a certain pH could be had for storing yeast under Starsan.


----------



## Danscraftbeer (17/4/17)

Another thought it may mutate the yeast? I'm eager to use my mini kegs to catch the yeast. Using a jumper lead from the outpost of the kegmenter to the mini keg with the spunding valve on the mini keg so its still pressure fermented. Sanitized mini keg you could also add boiling water in it, seal it and let cool. (for highest sanitation etc) High Krausen yeast is pretty impressive how much you get and how white it is. I guess it would be the cleanest as well?


----------



## DJ_L3ThAL (17/4/17)

Mardoo had some info he mentioned about not collecting the first 24 hrs of high Krausen if top cropping due to something that comes out along with it (sorry can't remember what it was, maybe lipids?). So timing is also worth mentioning too.


----------



## Yob (17/4/17)

I rekon all the dirty yeast I had to clean out the fridge, the base, the walls, the door...

I 'think' the yeast Ive got is good and certainly collectable.

Starsan 'residue' ends up as nutrient for yeast, something to do with the acidity of the wort if I remember correctly, might be a different story with the neat solution, I dunno but Ive rinsed the yeast in sterile water and will freeze some off..

I replaced that bottle pictured with a 3lt bottle and sterile water after an hour or so and have that to rinse yet so will compare pitches when I do another RIS.. which to be fair may be a few months now :blink:


----------



## Danscraftbeer (17/4/17)

DJ_L3ThAL said:


> Mardoo had some info he mentioned about not collecting the first 24 hrs of high Krausen if top cropping due to something that comes out along with it (sorry can't remember what it was, maybe lipids?). So timing is also worth mentioning too.


That works in practice. My experience is that if you have overblow its well after 24 hours. 48 to 72 hours being of the full boar that you wrangle in a blow off etc.


----------



## Yob (17/4/17)

Danscraftbeer said:


> That works in practice. My experience is that if you have overblow its well after 24 hours. 48 to 72 hours being of the full boar that you wrangle in a blow off etc.


I think he means the first 24hrs of high krausen and agree, Ive read in places that the first 'cream' should be discarded... but that's not my issue..


----------



## Danscraftbeer (17/4/17)

That's still good I think. First 24 hours krausen developes then breaches its containment after 24 hours.

I just pitched a 1.084 with said collected yeast and its kicked off well within 8 hours. Nottingham at 15c start.
Now I am about starting at low temps to tame things.


----------



## Yob (17/4/17)

the pictured explosion was at 17'c 

Greenbelt is ace..

my next strain Im going to concentrate on developing is 1272/1728 combo :super:


----------



## nosco (17/4/17)

I wouldnt have a clue but according to this vid the surfactant in Starsan, along with the phosphoric, will kill yeast over time but phosphoric acid wont above a pH of 2 and no more than 30 minutes. Thats probably completely incorrect.?. So I guess it depends on the health of the yeast and the time its in the Starsan. Just to muddy up the thread a bit  

https://www.youtube.com/watch?v=0JC9n50RdVo

https://www.youtube.com/watch?v=9LXEAZbei_8

Some great vids on both channels.


----------



## Yob (17/4/17)

thanks Dan, it's the time factor that I was wondering about, I'd_ 'guess' _that 24hrs is maybe ok..

I think I'll just have to take one for the team and do the trial, I rekon Ive got 2 vials to save, and more out of the sterile water so a side by side_ 'should be'_ easy enough.. er.. if I can get some time... :blink:


----------



## MHB (18/4/17)

I would toss it, just on general principal, yeast collected for repitching should be as contaminate free as possible and ideally as unstressed as you can make it.
The two concerns are the Acidity and the Detergent that make up Star San.
Yeast can survive exposure at pHs' as low as 2 for a short time, at 4pH for quite a long time. Any lower than 4 (about the internal pH of a yeast cell) interferes with the action of the Proton Pump mechanism that transports nutrients into and waste out of the cell. Too long and the cell dies, but even short times can damage (read Stress) the yeast and it may not recover or ferment in the way we expect.
Detergent interferes with head formation and retention, we all know that. Detergents foam and beer foams, but the mechanisms' are very different and compete for the other foam building ingredients in the beer, the net result being less foam on the beer (FOB). The detergent in Star San is a shocker its pretty much non biodegradable and cant be broken down by the yeast, so any in the beer will persist and interfere with the head to some extent.

Yob I would have thought you wouldn't be short of good healthy yeast to choose from, so why the hell would you even consider risking even possibly contaminated yeast.
Mark


----------



## Yob (18/4/17)

Good details mark, thanks. 

I like to keep samples of my very active yeast, I did swap this container out for one with sterile water so I've still got plenty to rinse and store.

Cheers


----------



## damoninja (18/4/17)

nosco said:


> https://www.youtube.com/watch?v=0JC9n50RdVo


I was just about to say it's gram negative so yes


----------

