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Comment by _0nac | Hacker News Reader

Skeptics StackExchange has a good takedown of this. TL;DR: Yeast ADH requires a neutral to alkaline environment to work, but the stomach is extremely acidic, so it's not going to do anything.

http://skeptics.stackexchange.com/questions/20381/does-eatin...

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What about the small intestine? I'm reading that about 80% of alcohol is absorbed there after leaving the stomach and that most of the small intestine has pH between 7-8.

http://prevention.gwu.edu/alcohol-absorption

http://microbewiki.kenyon.edu/index.php/Small_Intestine

Anyway, I can't see the utility of drinking without the expected effects.

I go to many craft beer festivals just to "taste" new beers. My main goal when attending beer festivals isn't to get drunk, but to taste a diverse list of new beers. It would be a big win for me if I could sample more and get drunk less.

If your goal sincerely is to taste more instead of feeling the effects of alcohol, why not spit the beer out? This is de rigueur among serious wine tasters for exactly this reason.

I have had great luck doing strenuous exercise, drinking moderate amount of water and taking some vitamin b 4-6 hours before drinking. Seems to double my tolerance.

Not a doctor so im just speculating, but wouldn't the ADH still be rendered useless when it goes through the stomach on the way to the small intestine? Perhaps this means it would work going the other direction, lol.

Not necessarily, you'd be surprised just how hardy both the yeast granules (really sporulated yeast) and ADH can be. I've actually done some research in this area (for unrelated reasons) but here's the a "must read" paper from 1975 if you're curious: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1165444/

"were studied in the pH range 4.9--9.9 at 25 degrees C and in the temperature range 14.8--43.5 degrees C at pH 7.05."

Forgive me if I am missing something obvious, but isn't that outside the range of a typical stomach's pH range? If so, how does this study relate to the conditions inside a stomach? Im basing these questions on what I saw in that skeptic.exchange link posted above, again im a total layman.

Edit: Thanks for the answers, aroch! :)

Stomach pH ranges between 1-5, what you eat contributes significantly to the variance in pH. The "active" yeast that's sold is actually the inactive spore (not actively budding) and low pH environments promote staying inactive. ADH is produced by metabolically active yeast, which theoretically would be yeast that reaches your intestines (indeed, we have "native" yeast in our intestinal tract).

Whether or not yeast would make it that far and then being to bud and produce ADH again, I couldn't really say. I never looked at human-ingestion of colonies.

ADH itself can be denatured in low pH environments but will renature and self-fold into an active tertiary structure when brought back to neutral/slightly basic pH.

Are you sure the enzyme would need to operate in an acidic environment?

Intact yeast cell membranes would be pretty capable of keeping ions out (thus some pH isolation), but I imagine they would be more permeable to small relatively uncharged substances as ethanol.

I see no immediate reason why not many of the yeast cell might act tiny bioreactors, keeping a somewhat controlled internal environment, where ethanol might diffuse in and be degraded. Can someone here think of any reason for why this would not be plausible?

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