[bartender]

Can alcohol be produced without yeast?
I am trying to settle a gentleman's bet, and have found little info to help settle the issue.
I have tried to 'google' the info, but have only come up with with sites that want to sell me some brewers yeast, or beer kits and distilation equip.
The perameters of the arguement are broad, and are summed up in the first line. The only supporting info I have been able to find are in the attached pdf.

[Garneck]

Technical alcohol - yes
C2H4 + H2O = C2H5OH

Alcohol to drink - no.. or at least you'd better not drink it  

[bartender]

So, without yeast, the alcohol would not be potable?

[Donaldson Tan]

industrial ethanol is produced without yeast. it's produced on a large scale via hydration of ethene using phosphoric(V) acid as catalyst and steam. there might be phosphoric acid or methanol produced in the process, thus industrial ethanol should never be drank. these are toxic compounds. however, for industrial purposes, the traces are negligible.

[movies]

It would be possible to purify ethanol made in a laboratory to the point that it was more pure than the ethanol you get from yeast!

The danger in drinking it is the traces of toxic compounds that are common in laboratories.  It would be possible to purify these to levels below the threshold of toxicity though, in principle.

Think about it, asprin is made in a laboratory too, and you don't think twice about ingesting that.

[chloral]

Acetic acid (vinegar is a dilute solution of acetic acid) can be reduced by Lithium Aluminium Hydride to give you ethanol.

[ATMyller]

You could actually ferment sugar in to alcohol without actually using yeast, using the enzyme extracted from yeast. And it would be drinkable.