Tomato Jelly - cooking recipe

Ingredients

1 3/4 cups tomato juice (can use 14 oz. canned juice from store)
1/2 cup lemon juice
4 cups sugar
1/2 teaspoon butter (optional)
1 (3 ounce) envelope liquid pectin

Preparation

Combine tomato and lemon juice in a large pot.
Add sugar and butter (if using-the butter is 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 pectin.
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 1/8 inch of tops.
Wipe jar rims and threads clean.
Cover with two-piece lids.
Screw bands tightly.
Process 5 minutes in boiling water bath canner.