The Science Behind Freezing Nuts for Storage.
Nuts can go rancid due to the oxidation of their unsaturated fat content, which produces compounds that give them an oily, stale flavor. Storing nuts in the freezer in a hermetically sealed glass jar or with multiple layers of plastic can slow down the oxidation process and prevent the formation of free radicals. Eating rancid nuts is not harmful, but it's best to consume them before they go bad. Nuts with a large surface area, such as walnuts, are more prone to rapid rancidity than compact nuts like almonds.