5 cups grape juice
1 (1 3/4 ounce) box dry pectin
7 cups sugar
1/2 tsp butter
3 teaspoons ground cardamom
Measure 5 cups grape juice and pour into a 5-quart kettle.
Add the pectin and butter. Cook over high heat, stirring constantly, until the mixture comes to a full, rolling boil. Boil rapidly one minute, stirring constantly.
Add sugar and cardamom and boil rapidly again for one minute.
Remove jelly from heat, skim off foam, and pour into hot sterilized jars, leaving 1/2-inch space at the top of each. Seal airtight.