At what alcohol levels do bacteria die out in

[HumanBeing25]

And, are brewing yeast better at surviving the alcohol than bacteria?

 

[JonM]

Well, it'd help if we knew what you're asking about specifically. Are you trying to cultivate a particular type of bacteria like lactobacillus, or are you asking about something else, like how to remedy an infected batch? Or just curious?

 

[HumanBeing25]

Well, it'd help if we knew what you're asking about specifically. Are you trying to cultivate a particular type of bacteria like lactobacillus, or are you asking about something else, like how to remedy an infected batch? Or just curious?

Curious. Do yeast die before normal bacteria (the bacteria you'd normally find in an infected brew or a sanitized brew), and at what alcohol percentages? I don't want to be drinking a dangerous bacteria cocktail.

 

[DrunkleJon]

Bacteria is used in beers to sour. Nothing pathogenic can survive in beer. If your beer gets infected, it may not taste good, but it will not hurt you.

https://www.homebrewtalk.com/f163/nothing-can-hurt-you-can-live-beer-confirmed-397067/#post5005390

 

[JonM]

Are you making beer? I ask because I thought I saw something about fermenting powdered eggs and flour, and houseflies getting into it. Bad stuff might be able to survive in a something like that.

 

[HumanBeing25]

Are you making beer? I ask because I thought I saw something about fermenting powdered eggs and flour, and houseflies getting into it. Bad stuff might be able to survive in a something like that.

Haha, you're right, but I'm making two separate batches with separate stuff in them

And I'm a bit of a sissy when it comes to drinking or eating stuff I don't know what's in

 

[HumanBeing25]

Bacteria is used in beers to sour. Nothing pathogenic can survive in beer. If your beer gets infected, it may not taste good, but it will not hurt you.

https://www.homebrewtalk.com/f163/nothing-can-hurt-you-can-live-beer-confirmed-397067/#post5005390

Cheers, Jon

 

[Calichusetts]

As low as 1.8%, probably lower. This was the typical beer for kids before water was safe.

 

[pjj2ba]

Die is a pretty specific event. 70% ethanol will KILL most microbes. Different bacteria are going to have different tolerances, just like different strains of yeast do. That being said, lots of microbes are not too fond of having much alcohol around. It might not kill them, but they won't be happy, and usually will just sit there dormant and not be an issue. The only way to have a beer with NO bacteria in it would be to run it through a sterile filter after fermentation. And then you'd have to do the transfer to an autoclaved keg/bottles, or there will once again be a tiny bit or bacteria around.

 

[jro238]

Curious. Do yeast die before normal bacteria (the bacteria you'd normally find in an infected brew or a sanitized brew), and at what alcohol percentages? I don't want to be drinking a dangerous bacteria cocktail.

It *all* depends on what bacteria you are talking about.

I did a quick literature search and found ecoli's ethanol tolerance is about 7.5% whereas lactobaccilus (some strains at least) can grow in 20% ethanol. It sounded like the majority of lactobaccilus is fine growing in up to about 16% ethanol. (Gold et al., 1991) (I just provided the ecoli info since it was in the paper, ecoli is not at all good at surviving in beer).

Note, however, that these are not concentrations that will KILL these bacteria, just what they will grow in. We use 70% ethanol in the lab to sterilize (at least very close to sterilize) anything that cant be autoclaved.

EDIT: forgot to add that most brewing yeast is happy up to ~13% ethanol (again depends on strain though). It would take more than this to actually kill them though.