4-1/2 to 5 pounds rhubarb (4-1/2 to 5 quarts), cut into 1 inch pieces
7 cups sugar
1 to 2 drops red food coloring, optional
2 (3-ounce) pouches liquid fruit pectin
Grind the rhubarb in a food processor or grinder. Strain through a jelly bag, reserving 3-1/2 cups of juice. Pour juice into a large kettle; add sugar and food coloring if desired. Bring to a boil over high heat, stirring constantly. Add pectin; bring to a full rolling boil. Boil for 1 minute, stirring constantly. Remove from the heat; let stand a few minutes. Skim off foam. Pour hot mixture into hot jars, leaving 1/4-in. headspace. Adjust caps. Process for 10 minutes in a boiling-water bath.