Banberry Jam - cooking recipe

Ingredients

2 1/2 cups ripe strawberries, hulled and crushed
1 3/4 cups ripe bananas, peeled and mashed
2 tablespoons bottled lemon juice
7 cups sugar
1/2 teaspoon unsalted butter (optional)
1 (3 ounce) envelope liquid pectin

Preparation

In an 8-quart pan, combine the strawberries, bananas, lemon juice, sugar and butter.
Over medium-low heat, stirring constantly, heat the mixture until the sugar is completely dissolved.
Increase the heat to medium-high and bring the mixture to a full rolling boil, stirring constantly. Stir in the entire contents of the pectin pouch.
Return the mixture to a full rolling boil, stirring constantly.
Boil, stirring constantly for 1 minute.
Remove the pan from the heat.
Skim off any foam.
To prevent the jam from separating in the jars, allow the jam to cool 5 minutes before filling the jars. Gently stir the jam every minute or so to distribute the fruit.
Ladle the hot jam into hot jars, leaving 1/4-inch headspace.
Wipe the jar rims and threads with a clean, damp cloth.
Cover with hot lids and apply screw rings.
Process half pint jars in 200\u00b0F (93\u00b0C) water bath for 10 minutes, pint jars for 15 minutes.