What are “non-wine Bacillus” and how did they get into my wine?
There are thousands of species of bacteria that, fortunately, cannot reproduce in wine due to the low pH and high alcohol content. Some species, however, form endospores that are resistant to temperature, alcohol, pH changes, etc. These propagules may survive in wine, germinate and reproduce rapidly on the rich media that is used for microbial plating. They sometimes produce large spreading colonies that can obliterate the colonies of wine bacteria and yeast.
