Electrolysis of Beer

Electrolysis of water, means that the water is separated into hydrogen and oxygen. As beer also includes water, I initially thought electrolysis of beer would cause the water to separate, and the hydrogen and oxygen given off gas, leaving behind a higher concentrate alcohol.

However then realise that ethanol is also in beer (and is what makes you drunk it seems), and like water has an OH bond, so would the electrolysis also cause that to break?

(also does the rest of the molecule affect the strength of the OH bond, either stronger or weaker?)

• Sounds like a horrible thing to do to good beer! – Jon Custer Sep 16 '14 at 21:55
• The beer will conduct electricity mainly because of ions like Na, H, Cl and HCO3. Any such experiment end up with hell of non-separable dirt on anode: the mixture of chlorine, percarbonates and products of their reactions with organic and anode itself. – sa7 Nov 8 '16 at 14:42
• At best it will smell like bleach :) – sa7 Nov 8 '16 at 14:46

It's hard to say what exactly you would end up with, but it probably wouldn't much resemble beer. The trick with electrochemistry is that a lot of things are electroactive and what reactions actually occur in a given reaction are not always easy to predict and depend on electrodes, solution composition, pH, applied potential, etc. Depending on your electrodes, ethanol may be significantly more easily oxidized than water. A quick literature search shows that platinum and gold are both decent catalysts for ethanol oxidation (platinum is commonly used in fuel cells for this reason), but even with other materials, I can't imagine any conditions in which one could easily enrich an ethanol/water solution in this way. Many organic compounds, probably including some that impart flavour, are likely to be oxidized as well, even if the ethanol wasn't, so it would certainly affect the taste.

Additionally, the electrolysis of water requires a large amount of energy, far more than distillation, so even if it would work, it would be an expensive way of doing it.

• My thoughts exactly! Incidentally, the electrochemical oxidation of ethanol over platinum can produce a whole pile of products, including acetaldehyde and acetic acid. If you're really lucky, you'll eventually get $CO_2$, so that C-O bond sticks around. – Geoff Hutchison Sep 17 '14 at 1:00