While you can sun-dry coriander leaves, they will lose a significant amount of their flavor and aroma compared to other drying methods. The heat and prolonged exposure to sunlight degrade the volatile oils that give coriander its distinctive taste.
Sun-drying is a traditional method of preserving herbs, but it's not ideal for all herbs, especially those with delicate flavors like coriander. Here's why:
Volatile Oil Degradation: Coriander's flavor comes from volatile oils. These oils are sensitive to heat and light. Sun-drying exposes the leaves to both for extended periods, causing the oils to evaporate and break down.
Loss of Color and Aroma: The vibrant green color of fresh coriander will fade significantly during sun-drying, turning brownish or yellowish. The characteristic aroma will also diminish.
Risk of Mold and Bacteria: Sun-drying can be inconsistent depending on the weather. If the leaves don't dry quickly enough, they can become susceptible to mold and bacterial growth, rendering them unusable.
Better alternatives for drying coriander include using a dehydrator at a low temperature, air-drying in a cool, dark, and well-ventilated space, or even freeze-drying, which preserves the most flavor.
To maximize flavor retention when drying coriander (regardless of the method), harvest the leaves in the morning after the dew has dried, and dry them as quickly as possible. Avoid bruising the leaves during handling, as this releases enzymes that can degrade the flavor.