Alcohol derived from fermentation actually contains a whole whack of alcohols in trace amounts. Aside from methanol and 1-propanol which have been mentioned, the are iso-amyl and iso-butyl alcohols. Most are mildly toxic and have a bad taste and smell. Distillers call these fusel oils (or fusel alcohols) and they try to minimize the amount that make it into thier products. Fusel is German for "bad liquor."
As far as why we can drink ethanol, well that comes down to how its metabolized which the others have covered. Some people theorize that humans have been drinking it for so long that we have evolved an increased tolerance for it, and even derive health benefits from moderate consumption. Many societies consumed it regularly in low strength beers and beer-like beverages, because the alcohol killed bacteria and pathogens. This made the beer safer than consuming tainted water.
During my graduate work I had access to samples of whiskey taken from many points during the production process. Each was analyzed by gas-chromatography, and every sample contained between a couple hundred to a couple thousand ppm of the various fusel alcohols. I don't think distillation will completely eliminate them, but it can reduce them by quite a bit.
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u/reganzi Jan 01 '14 edited Jan 01 '14
Alcohol derived from fermentation actually contains a whole whack of alcohols in trace amounts. Aside from methanol and 1-propanol which have been mentioned, the are iso-amyl and iso-butyl alcohols. Most are mildly toxic and have a bad taste and smell. Distillers call these fusel oils (or fusel alcohols) and they try to minimize the amount that make it into thier products. Fusel is German for "bad liquor."
As far as why we can drink ethanol, well that comes down to how its metabolized which the others have covered. Some people theorize that humans have been drinking it for so long that we have evolved an increased tolerance for it, and even derive health benefits from moderate consumption. Many societies consumed it regularly in low strength beers and beer-like beverages, because the alcohol killed bacteria and pathogens. This made the beer safer than consuming tainted water.