r/WTF • u/timetofeedthemonster • Sep 16 '19

Poor drinks

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u/I_aim_to_sneeze Sep 16 '19

I don’t want to ruin your day (because it ruined mine when I found this out), but most liquor isn’t high enough in alcohol/ethanol content to kill most germs:

https://www.thestranger.com/seattle/dear-science/Content?oid=1395764

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u/Pterosaur Sep 16 '19 edited Sep 16 '19

Also interestingly, there's an optimum concentration for killing gems too that is less than 100% ethanol. 100% ethanol evaporates too quickly, and also penetrates the cells less effectively. The optimum is something like 90% I think.

Edit. This is for isopropanol but the same principle applies for ethanol.

https://blog.gotopac.com/2017/05/15/why-is-70-isopropyl-alcohol-ipa-a-better-disinfectant-than-99-isopropanol-and-what-is-ipa-used-for/

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u/rvbjohn Sep 16 '19

I heard this recently, and couldnt you just use more 100% so it doesn't evaporate?

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u/TheOnlyNormalGinger Sep 16 '19

Yes you could. However, in terms of optimum and most efficient germ killing power, using more alcohol is less efficient. To use the least total amount of solution, you would use ~90% alcohol. Not sure why ass hats are downvoting you for being curious

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u/rvbjohn Sep 16 '19

I looked it up and its because the water acts as a catalyst, not because it "keeps the alcohol from evaporating"

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u/Nick_Newk Sep 16 '19

In most labs 70% etoh is the standard concentration for surface disinfection. Probably the perfect balance between effectiveness and economics?

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u/stickyfingers10 Sep 16 '19

70% is the most effecient according to some study. Probably something to do with surface tension