4 1/2 c. chopped, peeled ripe tomatoes (med. chunks)
1 lg. fresh lemon, thin sliced and halved
7 1/2 c. sugar
1 pouch Certo or Sure Jell
1/2 tsp. butter to prevent foaming
7-9 sterile jelly jars or sm. Mason jars

Bring tomatoes, lemon and sugar to full rolling boil in pot at least 4 times larger than contents.

Boil 5-10 minutes stirring constantly from bottom. Boil longer if you want thicker jam.

Add Certo and boil 2 more minutes. Remove from heat.