( from about 2 quarts berries. slightly underripe berries work best)
lemon, juice of
Fill 8 one-cup glass jars, sterilized according to the jar manufacturer's instructions, and then process according to the manufacturer's instructions.
Once the jars have cooled, to make sure all of the lids are sealed, push down on the center of each. If the lid pops back up, the jar isn't sealed; you should refrigerate and eat any jam in unsealed jars within a couple of weeks. Properly sealed jars will keep in a cool, dry place for several months.