Ground cinnamon, like most spices, doesn’t necessarily spoil in a way that makes it unsafe to consume, but it can lose its potency over time. To determine if ground cinnamon has gone bad, start by checking its smell. Fresh cinnamon has a strong, sweet-spicy aroma, but if it smells weak or musty, it’s likely lost its flavor. Next, examine the color; cinnamon should be a rich, reddish-brown hue.
If it has turned lighter or dull, it may have lost its potency. Lastly, taste a small pinch; if the flavor is lackluster or stale, it’s time to replace it. Store cinnamon in an airtight container, away from heat, light, and moisture, to maintain its freshness longer.