Archives for January 2018

70% Ethanol as a Sanitizer

I learned to homebrew back in graduate school. At first, I used bleach as a sanitizer because it was cheap and effective. Later, as I became aware of bleach’s potential to cause off flavors (and pit stainless steel), I switched to iodophor and later Star San. In my lab, however, as in biology labs worldwide, there was a sanitizer I used almost every day — 70% ethanol (sometimes written 70% EtOH). It didn’t occur to me until recently that this could be used in a brewery.

Ethanol, combined with a little water, is an effective sanitizer. Scientists have figured out that it is most effective at a concentration of 70% ethanol (v/v, with the remaining 30% being water) — although it is almost as effective throughout the entire range of 40–95%. The water helps the ethanol penetrate bacterial cells better. In biology laboratories, 70% ethanol is most often used to wipe down lab benches. (Glassware is generally sterilized by being autoclaved.) When sprayed on a clean surface, it kills bacteria in a manner of seconds. [Read more…]