If you have excess of mint leaves, you can dry and powder them and keep using for a long time. Wash the leaves well and spread them on a kitchen cloth for 2-3 hours to get rid of any excess moisture. Spread the leaves on a large baking tray and cover with a muslin cloth. Keep the tray in shade for 1-3 days until the leaves are completely dry. Add the dry leaves to a grinder and grind to make fine powder. Store in an airtight container at room temperature for 2-3 months.