According to the Whole Grain Council, amaranth has a slightly shorter shelf life than other grains when kept in an open container in your pantry – just four months compared to six months for wheat.

How do I know if my amaranth is rancid?

Nasty taste

A nasty taste from a meal containing the amaranth is the best way to know that the amaranth is bad. When you cook amaranth seeds, the meal should have a nutty and sweet flavor. Once you realize the taste of the seeds isn't sweet or nutty, you need to discard the meal as the amaranth seed may rancid.

Can you eat expired amaranth?

Amaranth can have a shelf life of up to one year if properly stored. Amaranth will not keep well if it is stored in a warm location or if it is exposed to sunlight. The flavor and aroma of amaranth will become bitter if it is stored improperly or if it is stored for an excessively long period of time.