Pull grapes from stems. Wash, discarding any bad ones. Pack in a large kettle. Add 1/2 inch water. Cook, covered, over medium heat until mushy." Work grapes through a sieve or Foley Food Mill. Run juice through strainer or jelly bag.

In large kettle, mix 2 quarts juice and 6 pounds sugar. Mix well. Bring to a boil, stirring constantly. Add 1 bottle of Certo and bring to rolling boil. Boil hard 1 minute, stirring constantly. Remove from heat. Skim off foam. Pour (ladle) into hot glasses or jars and seal or cover with paraffin (melted in coffee can in a pan of water), if not using self-sealing lids.