Less Sugar Canned Strawberry Jam - cooking recipe

Ingredients

6 pints strawberries, cut and crushed to yield 6 cups crushed berries
4 cups sugar
1/2 teaspoon butter (optional)
1 (1 3/4 ounce) box powder Sure-Jell (for less or no-sugar needed jam)

Preparation

Wash jars & screw bands in hot soapy water. Rinse well in warm water. Pour boiling water over flat lids in a pan off the heat. Let stand in hot water until ready to use. Drain well before using.
Fill canner half full of water and bring to a simmer.
Prepare berries by crushing 1 cup at a time using a potato masher.
Measure exact amount of fruit into an 8qt. saucepan.
Measure the exact amount of sugar into a separate bowl. (Do not reduce sugar or use sugar substitute. Look up no-sugar-needed recipes for those amounts.).
Mix 1/4 cup of sugar from measured amount with Sure-Jell. (Make sure to use the pink box of less or no sugar needed pectin!).
Stir sugar & pectin mixture into berries. Add 1/2 teaspoons butter to reduce foaming, if desired.
Bring to a full rolling boil (a boil that does not stop bubbling when stirred) stirring constantly.
Stir in sugar, quickly. Return mixture to a full rolling boil and boil exactly 1 minute, stirring constantly.
Remove from heat. Skim foam from top with metal spoon.
Ladle quickly into jars to within 1/8 inch of top.
Wipe jars' rims and threads and top with two-piece lids.
Place jars in water bath canner for 10 minutes, then remove from canner. Let cool completely before storing. Press on middle of the lid to make sure lids have sealed. If not, store in refrigerator.