Wash and dice the strawberries. An immersion blender or potato masher can be used for a finer texture.

Add them to a medium pot, and mix the sugar in well.

Stir continually over medium to high heat, and bring the strawberries to boil.

Once boiling, add the lemon juice and zest (if using).

Boil for about 15 to 20 minutes, or until the jam reaches 220F, stirring often.

Pour into a jar and allow to cool. Leave space for expansion when frozen.

Cover, refrigerate some and freeze the rest.