Author Topic: Acid Tolerant Yeasts  (Read 263 times)

Offline kramerog

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Acid Tolerant Yeasts
« on: June 01, 2019, 10:25:24 PM »
I am looking for candidate beer yeasts for making makgeolli, a korean rice "wine."  Makgeolli has a lot of lactic acid in it.  I made my first one with champagne yeast, which is not really my favorite, but it is robust.  Any recommendations for an acid tolerant yeast, ferments to 12% in an acidic environment without autolysis?

Offline a10t2

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Re: Acid Tolerant Yeasts
« Reply #1 on: June 01, 2019, 11:06:34 PM »
How acidic? There don't seem to be too many strains that have trouble with kettle sours starting at ~3.5 pH, for example.
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Offline RC

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Re: Acid Tolerant Yeasts
« Reply #2 on: June 01, 2019, 11:26:35 PM »
I've never seen pH tolerances reported for typical brewing yeast strains, but in general, they're tolerant down to about pH 2.0. This is supposedly close to the limit of Sac cer's tolerance, however, and it gets stressed from this level acidity. But if your beverage's pH is higher than this, you should perhaps worry more about alcohol tolerance than acid tolerance?

Offline kramerog

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Re: Acid Tolerant Yeasts
« Reply #3 on: June 02, 2019, 02:38:47 PM »
I experienced a commercial bottled kettle sour that smelled of burning rubber (from autolysis presumably).  It was much worse than the soy sauce I get in high gravity beers and sake so I'm more concerned right now about acid tolerance than alcohol tolerance, but I do want both.

I don't have pH info yet.

Offline kramerog

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Re: Acid Tolerant Yeasts
« Reply #4 on: June 02, 2019, 02:55:11 PM »
Interstingly, major acids in no particular order are lactic, acetic and succinic acid.

Offline reverseapachemaster

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Re: Acid Tolerant Yeasts
« Reply #5 on: June 02, 2019, 09:40:50 PM »
You can buy these Chinese yeast balls which are are used to make Chinese rice wine which is pretty much the same thing you are discussing. They are made with rice flour and include yeast, koji spores and lactic acid bacteria of some type. I have only played with them a little but they definitely will ferment out and create a lot of acidity if fermentation is not arrested.

I found them at a local Asian supermarket. If that is not an option I believe they are sold on Amazon as well. There is a long thread about using them on HBT.
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Offline Robert

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Re: Acid Tolerant Yeasts
« Reply #6 on: June 02, 2019, 10:03:55 PM »
I've never seen pH tolerances reported for typical brewing yeast strains, but in general, they're tolerant down to about pH 2.0. This is supposedly close to the limit of Sac cer's tolerance, however, and it gets stressed from this level acidity. But if your beverage's pH is higher than this, you should perhaps worry more about alcohol tolerance than acid tolerance?
Brewing yeasts are very acid tolerant.   Hence the efficacy of acid washing.
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Offline kramerog

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Re: Acid Tolerant Yeasts
« Reply #7 on: June 03, 2019, 01:56:54 PM »
You can buy these Chinese yeast balls which are are used to make Chinese rice wine which is pretty much the same thing you are discussing. They are made with rice flour and include yeast, koji spores and lactic acid bacteria of some type. I have only played with them a little but they definitely will ferment out and create a lot of acidity if fermentation is not arrested.

I found them at a local Asian supermarket. If that is not an option I believe they are sold on Amazon as well. There is a long thread about using them on HBT.

Nuruk has all the yeasts and enzymatic molds needed, but the yeasts produce what brewers would consider off-flavors in beers so some commercial yeast is a good idea to tame the wild flavors.

Offline kramerog

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Re: Acid Tolerant Yeasts
« Reply #8 on: June 03, 2019, 02:02:49 PM »
How acidic? There don't seem to be too many strains that have trouble with kettle sours starting at ~3.5 pH, for example.

The scientific literature I have seen on makgeolli has pH values above 4.  My makgeolli is pretty sour so I'm doubtful that the scientific experiments are representative of what I am making (still haven't taken any measurements on mine), but I suppose that the presence of succinic acid, which can be the most prevalent acid, might give the makgeolli a sourer impression than what the pH value would suggest.