- Makes 3 pints.
- 9 cups (about 4 lbs.) crushed blackberries
- 6 cups sugar
- 1/2 teaspoon lemon juice
Combine blackberries and sugar in a large Dutch oven; slowly bring to a boil, stirring occasionally, until sugar dissolves. Add lemon juice. Boil 30 to 40 minutes, stirring frequently, until jam reaches desired consistency. Skim off foam with a metal spoon. Quickly ladle jam into hot sterilized jars, leaving 1/4-inch headspace; cover at once with metal lids, and screw bands tight. Process in boiling water bath for 15 minutes.