The log POW of ethanol is −0.18 according to Wikipedia, i.e. in a two-phase system ethanol would preferrably accumulate in the aqueous phase, but not by much.

Suppose I wanted to lower the alcohol concentration in a drink, how well would adding some vegetable oil, mixing and removing the top layer with a straw work? What other parts of the drink are likely to accumulate in the oil? Which (unwanted) side effects can I expect?

Edit: Definition of Drinks

I'm interested in the effects on different types of drinks/alcoholic beverages from low-alcohol content beers to wines, whiskeys, vodkas and Stroh.

PS: While this may sound like a question for the cooking subsite, I am only interested in the chemistry.

  • $\begingroup$ It's somewhat broad, depending on drink. In general, it's not particularly good idea. You sure could extract alcohol from, say, whisky, but a little of fat would stay in water phase and not only ethanol would get extracted... Taste would suffer. $\endgroup$ – Mithoron Apr 17 '19 at 20:43
  • $\begingroup$ Fats rather decrease the effect of alcohol in vivo. :-) $\endgroup$ – Poutnik Apr 17 '19 at 20:46
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    $\begingroup$ What kind of drinks are we talking about, strong liquor, longdrinks, wine? Depending on the alcohol content, you will have quite a large solubility of the oil in the aqueous phase. This is going to taste real funny. $\endgroup$ – Karl Apr 17 '19 at 21:09
  • $\begingroup$ Much simpler method: Freeze your drink, pour out the remaining high alcohol content liquid, and then thaw the rest. Probably more often used to rescue the pure spirits from nasty, colourful alcopops. ;-) $\endgroup$ – Karl Apr 17 '19 at 21:13
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    $\begingroup$ Liquid-liquid extraction, repeated one or more times, is a common isolation/purification method. However in a "drink" you have to consider both ways that this works. Some of the oil will dissolve into the water phase and compounds other than ethanol would go into the oil phase. The result would probably be a very funny tasting drink. $\endgroup$ – MaxW Apr 17 '19 at 21:14

Liquid-liquid extraction is a widely used method, but it's normally used the other way round: You add e.g. ether to a solution of your valueable substance X in water, separate the phases, and evaporate the ether to get pure X. Add some more ether to the aqueous phase, etc, two-three times.

Now you can be quite sure that you have recovered all of your substance X, but also your aqueous phase will be saturated with ether. No problem if you'd discard it anyway, not so good for drinking. :-/

It's also bad if X, like ethanol, is well soluble in both phases. For hard liquor, the whole mixture is likely totally miscible, and for beer, you'll need a lot of oil to get any significant effect. And then what do you do with the ethanolic oil afterwards?


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