4 tablespoons water Put grapes in kettle with water. Heat and mash the grapes. Continue cooking, and as mixture thickens, stir frequently. When thicker, put through a fruit press and remove skins and seeds. Return to heat and cook slowly until thick.
Screw lids on tightly.
Process pints and quarts for 10 minutes in boiling water-bath. Remove jars from canner and complete seals if necessary. Cool on wire rack. Remove spice bag, add gelatin mixture and stir to dissolve. Add a few drops of red food coloring if desired.