Servings About 8 (1-cup) jars or 128 servings, 1 Tbsp. each
Wash grapes
Stem grapes and discard any that are not fully ripe or damaged.
Crush grapes thoroughly, 1 layer at a time.
Place in large saucepan; add water. Bring to boil. Reduce heat to low; cover and simmer 10 min., stirring occasionally.
Place small holed colander over a large bowl. Pour prepared fruit into colander. Let stand until well drained.
Measure exactly 1-1/4 qt. (5 cups) prepared juice into 6- or 8-qt. saucepot.
Stir pectin into juice in saucepot. Add vegetable oil to reduce foaming. Bring mixture to full rolling boil (a boil that doesn't stop bubbling when stirred) on high heat, stirring constantly.
Stir in sugar. Return to full rolling boil and boil exactly 1 min., stirring constantly.
Remove from heat. Skim off any foam with metal spoon.
Ladle immediately into prepared jars, filling to within 1/4 inch of tops.
Wipe jar rims and threads. Cover with 2-piece lids. Screw bands tightly. Place jars on elevated rack in canner. Lower rack into canner. (Water must cover jars by 1 to 2 inches. Add boiling water, if necessary.)
Cover; bring water to gentle boil. Process 5 min.
Remove jars and place upright on towel to cool completely. After jars cool, check seals by pressing middle of lid with finger. (If lid springs back, lid is not sealed and refrigeration is necessary.)