Blackberry Jelly - cooking recipe

Ingredients

2 1/2 quarts fully ripe blackberries
1/4 cup lemon juice
7 1/2 cups sugar
6 ounces liquid pectin (2 pouches)

Preparation

Crush berries and strain through a jelly bag to get 4 cups of juice.
If you are slightly short of juice, add small amounts of water to the pulp in the jelly bag, to squeeze out more juice.
Combine blackberry juice with lemon juice and sugar in a large saucepan, mixing well; bring to a boil over high heat, stirring constantly.
Immediately stir in pectin and return to a full rolling boil, stirring constantly.
Remove from heat and skim off foam with a slotted metal spoon.
Pour into sterilized half-pint jars (you will require about 8), leaving 1/2\" headspace.
Remove air bubbles.
Adjust caps.
Process in in water bath canner for 10 minutes.
When cool, check seals, and refrigerate promptly any that have not properly sealed.