Coriander roots can be stored fresh, refrigerated, or frozen. For fresh storage, treat them like a bouquet of herbs, trimming the ends and placing them in a jar of water, optionally covered with a plastic bag and refrigerated. For longer-term storage, freezing is an excellent option, preserving the flavour for months.
Here's a more detailed breakdown:

Fresh Storage (Refrigeration):
1. Prepare:
Remove the roots from the coriander bunch, wash them thoroughly, and trim any damaged ends.
2. Refrigerate:
Place the roots in a jar or container with a little water at the bottom, ensuring the water doesn't submerge the stems.
3. Optional Covering:
Some suggest loosely covering the container with a plastic bag to help retain moisture and prevent wilting.
4. Change Water:
Refresh the water every few days to keep the roots fresh.
Freezing:
Prepare: Wash and dry the coriander roots thoroughly.
Chop (Optional): Some prefer to chop the roots before freezing for easier use in recipes.
Freeze: Place the roots (whole or chopped) in freezer bags or containers.
Use: Frozen coriander roots can be used directly from the freezer, adding flavour to soups, stocks, and sauces.
Other Tips:
Drying: Coriander roots can also be dried and stored in airtight containers in a cool, dark place for up to a year.
Aroma: Freshly washed coriander roots have a strong, distinctive aroma.
Flavour: Coriander roots offer a unique and flavourful addition to various dishes, especially in Southeast Asian cuisine.