Some cooks prefer to buy certain spices whole, peppercorns being the best known example. Cumin, fennel, coriander, and nutmeg are some others. It is said that whole spices do not expire - or do they?
Fact is, whole dried spices do in fact “expire” – that is, lose potency and flavor. It's a slow process, but according to McCormick (the spice merchants) and other sources, after 2-3 years you can expect some loss of flavor. Of course, pre-ground spices lose flavor a lot faster. Because this loss is gradual you might not notice it. This is why some folks date their spice bottles upon purchase.
