I have a significant spice collection. Most I don't remember buying, which leads me to believe that they have probably 'expired.' Spice Advice gives us a more thoughtful approach to estimating spice freshness than my supposin'. Their first tip is doing a visual check:
- Green, leafy herbs will fade upon aging.
Be aware; however, that different herbs naturally vary in color and should not always be compared against each other. For example, tarragon is naturally greener in color than rosemary. Additionally, some dill products contain the flower portion, giving them a more yellow color than those without the flowers.
- Red colored spices, such as paprika, red pepper and chili powder will turn from red to brown in color.
To read the next 2 steps, visit this page at Spice Advice.