A type of fungus that grows on food as fuzzy or discoloured patches and can spoil it or, in some cases, produce harmful toxins.
For soft or moist foods, no. Mould can send roots deep below the surface, so these foods should be discarded. Some hard foods like hard cheese can be salvaged by cutting well away from the mould, but discard anything questionable.
Much mould simply spoils food, but some moulds produce harmful toxins called mycotoxins. Because you cannot tell by looking which is which, unexpected mould growth should be treated cautiously and the food discarded.
Blue cheeses and some other products use specific, controlled mould strains that are safe to eat and part of the intended food. This is different from unexpected mould appearing on food that was not meant to have it.
Mould releases spores into the air that settle and grow wherever there is moisture and food. Damp storage, condensation and poor ventilation encourage it, and spores can spread from spoiled items to fresh stock nearby.
Store food correctly, keep areas dry and well ventilated, rotate stock, check deliveries and stored food, and clean regularly. Discard mouldy soft foods promptly and fix any sources of damp.