1 quart water
2 cups firmly packed fresh basil leaves, finely chopped
1 package (1-3/4 ounces) powdered fruit pectin
3 drops green food coloring, optional
5 cups sugar
In a large saucepan, bring water and basil to a boil. Remove from the heat; cover and let stand for 10 minutes. Strain and discard basil. Return 3-2/3 cups liquid to the pan. Stir in pectin and food coloring if desired. Return to a rolling boil over high heat. Stir in sugar. Boil for 1 minute, stirring constantly. Remove from the heat; skim off foam.
Pour hot liquid into hot sterilized jars, leaving 1/4-in. headspace. Adjust caps. Process for 15 minutes in a boiling-water bath.