Saffron eventually expires -- after one to four years -- depending on whether it's whole or ground. Like many spices, saffron eventually loses its flavor and potency and can be too old to use in cooking. To keep saffron fresh longer, store it in an airtight container away from heat, moisture and sunlight. Avoid using saffron directly from the bottle over something that is being cooked -- that is the quickest way to spoil spices. Knowing when to purge saffron from your spice cabinet ensures that you use only the freshest flavorings when cooking.
Look at the expiration date on the bottle of saffron. If it is past the expiration date, throw the saffron away. Ground saffron has a typical shelf life of one to two years. Whole spices usually stay fresh longer, up to four years. The larger and more whole a spice is, the slower it loses its flavor.
Look at the color of the saffron. If the saffron has faded from its original orange-red color, it may no longer be fresh.
Crush the saffron in your hand. If it has a faint aroma or is excessively brittle, it is too old to use.