When I get a surplus of tomatoes, I put them into freezer bags and freeze them solid for stewed tomatoes in the winter. When you want to use them, I put a pot of hot water to boil on the stove. I put the frozen tomato into the boiling water for about 5-10 seconds. I pick it out with my tongs and run the tomato under the tap and the skin peels right off. I do all the skins off the tomatoes and then dump out the water. I wait for the tomatoes to thaw a bit and core and cut them up and put them in the pot to cook.