Mash berries or use processor to finely chop. Measure prepared fruit.
Stir in lemon juice.
Gradually add pectin and mix thoroughly. Set aside for 30 minutes stirring every 5 minutes.
Stir in corn syrup and stir well.
Measure sugar. Gradually add sugar and stir constantly until sugar is dissolved and no longer grainy.
Ladle into clean jars.
Let stand at room temperature for 24 hours. Refrigerate for immediate use or freeze for up to 6 months.
Notes
Any combination of berries will work in this recipe. Be sure to use a total of 3 cups of fruit.
Berries should be chopped, but not pureed.
Freeze jam for up to 3 months, or refrigerate for up to 3 weeks in airtight containers. Leave an inch of extra space at the top of freezer containers to allow for expansion.