Place berries in a large stainless steel or enamel saucepan. Bring to a full boil over high heat, stirring continuously. Boil hard for 1 minute, continuing to stir. Add sugar, return to a boil, and boil until mixture reaches 220ËšF on a candy or instant thermometer. Ladle into clean jars for storage in the freezer or into sterilized jars if processing with a water bath. If water-bath processed, this jam can be stored at room temperature.