A lot of normal intake includes a little bid of alcohol, orange juice, coca-cola - anything with sugar will ferment to produce alcohol.
That one or two percent of us who are bastards is always screwing things up for those of us who just want to play things fairly straight and enjoy our lives and jobs. Sexual harrassment, racial complaints, people going postal, are developed, and the less obvious like the cockpit gun debate get done tremendous damage by these cads.