Clean berries and cook in water until skins pop. Strain through a sieve. Add sugar and gelatin that has been softened in water as directed on the gelatin box. Mix well by stirring. Heat until thoroughly dissolved. Cool and add lemon juice, mixing well.
Pour into 2 trays (about 2/3 full). Place trays in freezer. Freeze until solid, for 3 - 4 hours. Cut into chunks for serving. Will keep in freezer at least a week.
Makes 6-8 servings