Hi Jay all nuts, grains, and fruit has their mold. which turns to fungus. I follow the food rules by Dr Clark she tells you how to prevent mold on nuts (it is not visible to the naked eye most of the time) I make my own nut butter, she recommends putting in 1/4 tswp vitamin c to 1 pint to prevent mold. that is why most of the products at the health food store has "natural flavor" it is msg to disguise the taste of mold. Judy