The other day, I went on a mad search for strawberries; I didn't realize that the season was ending so quickly! My usual local farm stand was out, but they had beautiful raspberries.
Start by washing the berries (I added 5 drops of lemon essential oil to the wash water as an extra antimicrobial wash) then mashing them in a single layer with a potato masher. You will need 2 cups of mashed berries for each pint of jam.
Add 1/3 cup of thawed apple juice concentrate to the berries in a deep, non-aluminum pan. (I made 3 pints worth so used 1 cup of concentrate).
Sprinkle the pectin (this recipe calls for 1 1/2 tablespoons per 2 cups of fruit; and make sure you use pectin designed for low- or no-sugar canning) over the fruit and juice mixture and stir well to combine.
Over high heat, bring to a rolling boil that cannot be stirred down and boil for 1 minute. (Be careful, it is really hot and has a tendency to spit at you!)
Use a spoon to skim the foam off the surface of the jam. If desired, you can add 1/4 teaspoon of butter with the pectin before boiling to cut down on some of the foaming.
Ladle the hot jam into clean, sterilized jars (a canning funnel is indispensable), wipe the rim with a hot wash cloth, and cap with a clean, sterilized lid and ring tightened down gently.
Process in a boiling water bath (submerge the jars at least a couple inches below the surface of the water and put the lid on) 10 minutes if you live below 500 feet elevation (you will need to add additional time if you live at higher elevations, usually an extra 5 minutes for each 1000 feet).
The fruits of my labor: a fruit-heavy, tart rasperry jam! It even made an extra 12 ounce jar!