Red Tomato Jam

4 cups tomatoes
1/2 slice lemon
4 cups granulated sugar, divided

Scald tomatoes, peel. Squeeze out as many seeds and as much juice as possible. Measure 4 cups tomatoes into kettle. Add lemon and 1 cup sugar. Boil for 5 minutes.

Add 1 cup sugar. Boil for 3 minutes.

Add remaining sugar. Boil for 20 minutes. Pour hot liquid into sterilized containers; seal.