Chestnuts are among the least durable varieties of nuts—most other kinds of nuts will have a natural shelf life of around three months at room temperature.

How can you tell if chestnuts are bad?

Signs of Spoilage

Chestnuts can get moldy or inedible and dry if they get too old. If you see signs of extreme mold, smell a rotten odor or have chestnuts that are as hard as concrete, they're not suitable for eating.

How quickly do chestnuts go bad?

The nuts have a high moisture content which can cause them to spoil quickly. Fresh chestnuts, still in their shells, will keep for about a week in a cool, dry place. To store them longer, place them in a plastic bag - perforated to allow for air circulation - and refrigerate them for up to a month.