Berry Jam

As noted on Kitchen Chemistry by Dr. Patti Christie

Strawberry or other Berry Jam

From Certo package insert

Ingredients:  

• 4 cups crushed fruit (this is about 2 quarts of fresh fruit or 2.5 pounds of frozen, thawed fruit)
• 7 cup white sugar
• 1 pouch of liquid Certo

Method:
 

• Start the dishwasher with the jam jars. The best jars are the Mason Jars with the lid, glass jar and screw bands. To achieve the best seal, it is best to put the jam into a hot glass jar, so time the dishwasher accordingly.
• Prepare fruit. For berries, crush the fruit with a potato masher to the desired chunkiness.
• Measure the exact amount of prepared fruit into a 6 or 8 quart saucepan. It is best to use a pot in which the fruit does not go above about one quarter of the depth to prevent the jam from boiling over
• Stir sugar into fruit
• Bring mixture to full rolling boil ( a boil that does not stop bubbling when stirred) on high heat stirring constantly
• Stir in Certo quickly. Return to full rolling boil and boil exactly 1 minute stirring constantly. Remove from heat. Skim off any foam with a spoon.
• Using a 2 cup measuring cup, ladle quickly into prepared jars, filling to within 1/8 inch of tops. Wipe jar rims and threads. Cover with flat lids, then screw bands tightly.
• Invert jars for 5 minutes, then turn upright.
• After jars cool, check seals by pressing middle of lid with finger. If lid springs back, lid is not sealed and refrigeration is necessary.
• Let stand at room temperature 24 hours. Store unopened jams in a cool dark place up to 1 year. Refrigerate opened jams up to 3 weeks.
• Yield is about 8 cups of jam