Place tomatoes in hot water just long enough to remove skins. Core, skin and chunk tomatoes. Place in quart jars, add 1 teaspoon salt. Screw lids on tightly. Place jars (middle rack) in cold oven so that jars do not touch each other. Turn oven to 250 degrees. Cook for 1 hour and 15 minutes. Turn oven off, and remove jars only after cooled. Do not open oven door while oven is warm.