Because of the high acidity, tomatoes are among the easiest of foods to can successfully. Tomatoes for canning should be fully ripe, but firm. Peel by dipping them into boiling water for 20-30 seconds, then into cold water. The skin should be loose and will slip off easily.
Tomatoes can be processed using either the raw pack or the hot pack method. For raw pack, spoon whole or quartered tomatoes into clean, hot jars and press down lightly with a spoon. Do not add water as tomatoes will make their own juice. For hot pack, place quartered tomatoes into a saucepan and bring to a boil, stirring frequently. Pack hot tomatoes in their own juice into clean hot jars.
After packing, hand tighten lids and put jars into canner. Cover with boiling water and process. Raw pack tomatoes are processed 35 minutes for pints and 45 minutes for quarts. Hot pack tomatoes are processed for 10 minutes for either pints or quarts. Begin timing when the water returns to a boil.