12 Steps to Canning Tomato Sauce

Step 5, Boil Vegetables

We always use Roma tomatoes because they have far less liquid the other tomatoes. After a batch of tomatoes are ready we add the onion and pepper to the pot. You will need to boil the vegetable mixture to reduce the liquid and make the tomato sauce thicker. You need to keep the heat on medium after boiling starts and stir often. Add a few pats of margarine to the top of the pot to help reduce foaming.