Definitions for "Wild yeast"
Keywords:  yeast, wort, beer, deliberated, strain
Any yeast strain which was not deliberated introduced into the wort by the brewmaster. Though most wild yeasts are harmful to the beer, a very small minority of them are not.
Yeast that naturally occurs on grape skins.
Saccharomyces that haven't been hanging around man long enough, so they're not much good for baking bread or brewing beer, wine or mead.