posted 8 years ago
yeasts look like strands or a smooth solid cap (Vinegar Mother is a great example of this look). They will all be in the same color range (cream is the normal color range).
Molds will look fuzzy or hairy and not look at all like a yeast cap. Lots of different colors, greens, yellows, whites, browns, blues, any of these are an instant tip off that you are looking at a mold or molds
Mother Earth News has some great photos, or you can goggle vinegar mother pictures, lots of those are already public domain.