By adding the grated apple, which is a pectin packed fruit, it naturally jells the jam and gives it a pleasant tartness.
1 Pound Strawberries
2/3 Cup Sugar
1 Peeled Granny Smith Apple
1 Tablespoon Fresh Lemon Juice
Hull and quarter the strawberries. You may use fresh or frozen (thaw before using). In a heavy skillet combine the strawberries and sugar. Grate the peeled apple and stir into the strawberry mixture. Cook over a medium low heat. Stir and break up the strawberries until the sugar dissolves. Simmer for 15 minutes until the jam has thickened. Stir in the lemon juice. Transfer to a bowl or jar and let cool. Cover and chill for 2 ½ hours until set. Keep chilled and serve within 2 weeks. Makes 1 ½ cups.