Instructions

1. Peel, core and quarter tomatoes. (Head here for how to peel tomatoes and how to core tomatoes)
2. Place the tomatoes in a large saucepan and boil for 20 minutes uncovered. Scoop tomatoes into a food mill, then start twisting. Reverse direction to scrape out the rest of the tomatoes then continue with the rest of the tomatoes. If you don’t have a food mill, you can use a blender to blend the tomatoes in batches, and then use a sieve to filter out any tomato bits for the smoothest sauce texture.
3. Heat the olive oil in a separate large pot over medium heat. Add the onions, garlic and bell peppers and cook until tender, about 10 minutes taking care to make sure the garlic doesn’t brown.
4. Add in the salt, spices and sugar along with the tomato puree and bring to a boil. Simmer uncovered, stirring often to prevent burning, until thick. The initial volume will be reduced by roughly one-half. This should take about 1-3 hours depending on how thick you like your sauce.
5. Fill hot, sterilized canning jars with sauce, leaving 1 inch headspace. Remove any air bubbles and adjust headspace if needed. Wipe rimes of jars with a dampened paper towel and add lids.
6. Process using a pressure canner. For a dial-gauge pressure canner:  Process pints at 11 pounds pressure (PSI) for 20 minutes; 25 minutes for quart jars. If you live above 2000 feet altitude, process at 12 pounds pressure for the same time, 13 pounds pressure if you live above 4000 feet altitude and 14 pounds if you live above 6000 feet altitude. For a weighed-gauge pressure canner: Process pints at 10 pounds pressure for 20 minutes; 10 pounds pressure for 25 minutes for quart jars. If you live above 1,000 feet altitude, process at 15 pounds for 20 minutes for pint jars and 25 minutes for quart jars.