Bring a large pot of water to a boil. On the end of the tomatoes make a small "x" with a knife, piercing the skin. Add a few tomatoes at a time to the boiling water. Allow them to cook for 1 to 2 minutes before removing them with a slotted spoon or spider. Immediately plunge them into a cold water bath to help loosen the skins. Repeat until all tomatoes are in the cold water bath.
Peel the skins off the tomatoes and discard. Take 2 cups of the tomatoes and add them to a large nonreactive pot. Smash them with the back of a spoon to release their juices. Cook them over medium-high heat, stirring constantly, until they boil. Gradually add in the rest of the tomatoes and continue cooking to a boil. Boil gently for 5 minutes.
To Freeze
Allow the tomatoes to cool. Pack into freezer containers allowing room for expansion, and freeze.
To Can
Add in 1 tablespoon of lemon juice for each pint of sauce and 2 tablespoons for each quart. Fill hot, sterilized jars to 1/2" from the top. Put rings and lids in place and process in a boiling water bath (45 minutes for quarts and 35 minutes for pints).
Remove the jars to a clean, dry towel on a flat surface. Any jars that don't seal when they are cool can be placed in the refrigerator and eaten within a week.