Remove the skins by blanching tomatoes.Using a blanching basket, add tomatoes to boiling water for approximately 1 minute or until skins split. Place tomatoes in cold water to cool immediately, use your hands to slip the skins off.
Add peeled tomatoes to large stockpot and bring to a boil.
Simmer (uncovered) until thickened, stirring frequently.
Procedure for Food Mill (Removes Skins & Seeds)
Wash tomatoes.
Remove stems and bruises, slicing tomatoes in half.
Simmer tomatoes to soften. Use a potato masher to crush the tomatoes to start juices flowing.
Cool slightly and run tomatoes through a food mill to remove all skins and seeds.
Simmer (uncovered) until thickened, stirring frequently.
Now your sauce is ready for use. If you want to can the sauce just as it is, proceed using the directions below. You can also stop here and use the sauce in specific recipes, like spaghetti sauce.
Procedure for Canning Tomato Sauce
Start by preparing jars and getting water in the canner heating. You want the canner hot, but not boiling, when the jars are ready to be processed.If you are new to using a pressure canner, see this article for full pressure canning instructions. This includes more detailed information and step-by-step instructions on how a pressure canner works. See full water bath canning instructions here.
Hot Pack only
Add lemon juice to jar (1 Tbsp. per pint or 2 Tbsp. per quart).
Add 1 tsp. salt per quart or 1/2 tsp. per pint (optional, but recommended).
Fill hot jar, leaving 1” headspace.
Remove air bubbles. Wipe the rim clean and place seal and ring. Place jar in the warm canner. Proceed to fill all jars. Process according to directions below.
Notes
Processing with a Water Bath CannerPlace the jar in the warm canner. Proceed to fill all jars placing them in the canner.When all the jars are filled, bring the water in the canner to a boil. When a boil is reached that is when you'll start your timing. Process for the length of time on the chart below. Adjust for your altitude. After your time is over, turn the heat off remove the lid and allow the canner to rest for about 5 minutes. Then bring your jars up out of the water. Allow them to rest for another 5 minutes. Then remove the jars and place them a few inches apart on a thick towel to cool completely. Leave them alone for about 12 hours. When they are cooled remove the metal bands, check the seals, label the jars and store them away! Processing Times for Water Bath Canner (Hot Pack) Altitude - Pints - Quarts
0-1,000 ft - 35 minutes - 40 minutes
1,001-3,000 ft - 40minutes - 45 minutes
3,001-6,000 ft - 45 minutes - 50 minutes
Above 6,000 ft - 50 minutes - 55 minutes
Processing with a Pressure CannerPlace the jars in the warm canner. Proceed to fill all jars placing them in the prepared hot canner. Put the lid on the canner leaving the weights off. Bring to a boil. Watch for the steam to start coming out the vent pipe in the lid.Allow the steam to 'vent' for 10 minutes then put the weights on. Use the proper weight for your altitude (check the chart below) This is when pressure will start to build. When the pressure reaches the pressure required for your altitude (check the chart below) that is when you’ll start your time. Process for the full time indicated, adjusting the heat as needed to maintain the correct pressure for the entire time.When the processing time is completed turn off the heat. Do not remove weights yet. Let the canner sit undisturbed until the pressure comes back to zero. Do not try to speed up the cooling process.Remove the weight and wait 5 minutes.Open the lid to allow steam to escape. (carefully don't let it hit your face or arms!) Leave the lid setting on top of the canner slightly ajar and wait 5 minutes.Take the lid off the canner and remove your jars. (optionally you can wait another 5 minutes if the contents appear to be bubbling so hard it is coming out of the jars)Put the jars a few inches apart on a thick towel and allow them to cool to room temperature undisturbed. 12 hours is suggested.When the jars are cool, remove the metal bands, check the seals, and store the jars in a cool dark place.Processing Times for Pressure Canner (Hot Pack) Process pints and quarts for 15 minutes, adjusting for altitude.Adjustments forPressure Canner Altitude - Weighted Gauge0-1,000 ft - 10 pounds1,001-8,000 ft - 15 poundsAltitude - Dial Gauge0-2,000 ft - 11 pounds2,001-4,000 ft - 12 pounds4,001-6,000 ft - 13 pounds6,001-8,000 ft - 14 pounds
Adapted from: The National Center for Home Food Preservation