Adapted from Cooks.com
Note: this recipe takes about 3 days to make, but most of the work is on the third day. Start on a Wednesday night, or at the beginning of a 3-day weekend.
About 4 qts. cubed watermelon rind
3 tbsp. salt
3 1/2 c. vinegar + 1/2 c. water
6 c. sugar
4 sticks whole cinnamon
1 tbsp. whole cloves
Pare outer green peel from the firm white inner rind of 1 small watermelon, discarding any pink flesh. Cut in 1-inch cubes. Cover with cold water, add the salt and let stand overnight.
Drain, rinse with fresh water and drain again. Cover again with fresh water and bring to boiling. Simmer over low heat until cubes are just barely tender: DON'T OVERCOOK. Drain.
Combine the vinegar with the 1/2 cup water; add sugar; tie the spices in a small cloth bag (or place in a tea strainer) and add. Bring to boiling and cook 5 minutes. Pour over the rind cubes and let stand 24 hours.
Drain off the syrup and bring it to boiling, then pour it again over the cubes. Let stand 24 hours.
Bring all to boiling and simmer 5 minutes. Fill hot sterilized jars and seal. Makes about 7 pints.