This section is from the book "Preserving And Pickling", by Mary M. Wright. Also available from Amazon: Preserving and Pickling: Two Hundred Recipes for Preserves, Jellies, Jams, Marmalades, Pickles, Relishes and Other Good Things.
Select grapes that are just turning purple, and to each gallon of grapes add two pounds of sugar, one cupful of good cider vinegar, and one tablespoonful each of cinnamon, cloves and allspice, and one teaspoonful each of pepper and salt. Stew the grapes in just enough water to start the juice flowing; then pass through a sieve. Place the pulp, sugar, vinegar and salt together in a preserv ing kettle. Tie the spices up in a muslin bag and add to the fruit. Simmer slowly until of the consistency of ordinary catsup. Ripe grape catsup may be made in the same manner.