They're more closely related to urine than poop, in that poop is (mostly) the undigested foods. Urine is the byproduct of metabolic processes which are toxic and need to be removed. read more
They're more closely related to urine than poop, in that poop is (mostly) the undigested foods. Urine is the byproduct of metabolic processes which are toxic and need to be removed. Alcohol and acetic acid (the acid in vinegar) will (and do) kill the organism that created them. Aspartame is made by genetically modified bacteria, in the same way. read more
By watching fermentation under a microscope, Pasteur determined that it was yeast that produced alcohol, and that microorganisms in the air could sour the fermentation process. Pasteur discovered that heating alcoholic products -- as well as milk and vinegar -- would kill unwanted organisms. read more
Yeast, by and large, eat sugar and produce alcohol and various esters and phenols (and CO 2). To most brewers (and vintners), though, the only yeast of any consequence is Saccharomyces, and any other microbe is to be avoided at all costs. read more