Is my sourdough starter a contamination threat to my beer?

[TomFromEnfield]

Hi


I've just bottled up a batch of Saison and whilst doing so noticed my sourdough starter was sat there on top of the fridge. This got me wondering if the yeast/bacteria present in the sourdough might be a potential infection hazard to the beer I was bottling.

Does anyone know if the yeast/bacteria that live in a sourdough starter are the same sort of strains that might also survive in beer? The yeast starter is made up of just flour (rye, spelt, wholegrain flour - stuff you'd but in a UK supermarket) mixed in with water and allowed to 'start'. I'm not particularly worried about infection seeing as I clean and sanitize everything as standard when bottling and it's not like I'm throwing sourdough starter around the kitchen; just more curious about the microbial make up and whether it could take hold in wort or beer.

I realise that the yeast and bacteria on the flour has evolved to live in and on flour and that brewers yeast is designed to ferment wort. I'm just curious how much cross over there is and if the same yeast/bacteria strains in the sourdough might have a crack at my beer. Or if the sourdough yeast might just die out pretty quickly in the boozy environment within my primary.

Do I have an 'infection bomb' sat on top of the fridge? Is my starter pumping out noxious wild yeast and bacteria ridden fart-clouds across my kitchen contaminating every surface? Should I get the Dettol out? Are the kids' safe?

 

[strange-steve]

Yes, the acidity in sourdough comes from lactic acid produced by lactobacillus which is very much a beer spoilage organism. If you've ever tasted a lambic or a Berliner weisse, they are also soured with lactobacillus.

 

[TomFromEnfield]

Hi Steve, much appreciated. I headed to Google off the back of your comment and it looks like Lactobacillus plantarum, and Lactobacillus brevis can thrive in both.

 

[strange-steve]

Hey if you ever fancy brewing some weisse at least you have a nice healthy source of lacto plantarum which is perfect for the job :thumba:

 

[foxy]

Hi


I've just bottled up a batch of Saison and whilst doing so noticed my sourdough starter was sat there on top of the fridge. This got me wondering if the yeast/bacteria present in the sourdough might be a potential infection hazard to the beer I was bottling.

Does anyone know if the yeast/bacteria that live in a sourdough starter are the same sort of strains that might also survive in beer? The yeast starter is made up of just flour (rye, spelt, wholegrain flour - stuff you'd but in a UK supermarket) mixed in with water and allowed to 'start'. I'm not particularly worried about infection seeing as I clean and sanitize everything as standard when bottling and it's not like I'm throwing sourdough starter around the kitchen; just more curious about the microbial make up and whether it could take hold in wort or beer.

I realise that the yeast and bacteria on the flour has evolved to live in and on flour and that brewers yeast is designed to ferment wort. I'm just curious how much cross over there is and if the same yeast/bacteria strains in the sourdough might have a crack at my beer. Or if the sourdough yeast might just die out pretty quickly in the boozy environment within my primary.

Do I have an 'infection bomb' sat on top of the fridge? Is my starter pumping out noxious wild yeast and bacteria ridden fart-clouds across my kitchen contaminating every surface? Should I get the Dettol out? Are the kids' safe?

Similar question here.
https://aussiehomebrewer.com/threads/can-sourdough-infect-my-brewery.95885/

 

[Leon103]

Yes, throw it.

 

[dwhite60]

Been doing sourdough for over ten years. Have never had a contamination problem. I don't bake bread and brew the same week. Be thorough on your sanitizing.

All the Best,
D. White

 

[foxy]

You would more than likely have more yeast on your body, clothes and hair than would be coming out of the starter, even without your starter the kitchen would house more yeast than any other room.
I often make bread while I am brewing, though I brew outside my stir plate is in the kitchen stirring the yeast in the Erlenmeyer flask. I wouldn't be worried.

 

[Cwrw666]

You would more than likely have more yeast on your body, clothes and hair than would be coming out of the starter, even without your starter the kitchen would house more yeast than any other room.

Agree. Kitchens are probably overall filthier places than even your toilet.
Not really a problem though if your cleaning/sanitisation regime is up to scratch, but it's one of the reasons I brew less in summer when there's fruit flies about.

 

[TomFromEnfield]

Thanks for all the input. I think my cleaning and sanitisation is pretty good so I'll not lose any sleep over the sourdough.

 

[Graz]

Please don't lose any sleep. There's wild yeast pretty much everywhere. Key thing with brewing is a good cleaning / sanitation procedure and not leaving brews exposed to the air for too long without the intended yeast taking hold first. The time from the wort being cooled off, put into a fermenter and the yeast being pitched is the key thing.

 

[Hoppy]

As Graz said, bacteria/wild yeast is everywhere, how did your sour dough starter get.....started?
This is why it's important to chill your hopped wort ASAP and get your yeast in!