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.
Raw Pack only
Peel tomatoes.
Halve or quarter tomatoes. (You can leave small or roma tomatoes whole.)
Add lemon juice to hot jar, 2 Tbsp. per quart or 1 Tbsp. per pint. (For citric acid, use 1/2 tsp. per quart or 1/4 tsp. per pint instead of the lemon juice.) If desired, add canning salt (1 tsp. per quart or 1/2 tsp. per pint).
Pack tomatoes into jar, pressing down to fill space with juice.
Leave 1/2” 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 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 processing time is completed turn off the heat. Do not remove weights yet. Let the canner sit undisturbed until 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 Instructions for Water Bath CannerProcessing Times for Water Bath Canner (Raw Pack) Altitude - Pints and Quarts are Processed the Same0-1,000 ft - 85 minutes1,001-3,000 ft - 90 minutes3,001-6,000 ft - 95 minutesAbove 6,000 ft - 100 minutes Processing Instructions for Pressure CannerProcess pints or quarts 25 minutes, adjusting for altitude.Processing Times for Pressure Canner (Raw Pack) Altitude – Dial Gauge 0-2,000 ft - 11 pounds2,001 - 4,000 ft - 12 pounds4,001 - 6,000 ft - 13 pounds6,001 - 8,000 ft - 14 poundsAltitude – Weighted Gauge0-1,000 ft - 10 pounds1,001 – 8,000 ft – 15 pounds
Adapted from: The National Center for Home Food Preservation