• Place four dried black limes in a large mortar or molcajete.
• With a few firm hits with the pestle, crack the limes open. You can stop pounding when each lime has opened up - need not grind to powder.
• Transfer the cracked dried limes into a pan, and add 1.5 liters of water.
• Bring to a boil, then simmer for 15 minutes. The bubbling water would turn black as the dried limes release their juices and flavor.
• Switch off the heat, and stir in the sugar till it dissolves.
• Let the pan cool naturally to room temperature. Strain the drink into a clean bottle or jug with a tight-fitting lid, and discard the cooked black lime bits. Transfer the drink to the refrigerator to chill.
• Dried black lime cold drink is ready to serve.

To Serve:

• Place ice cubes into each glass. Drop in fresh mint leaves. Pour over the dried black lime drink. Enjoy!