Canning tomatoes is akin to putting summer in a jar. Fresh, bright tomatoes packed into Mason jars taste so good in the dark winter months. It’s a lot of effort, but the taste is beyond compare.

For many years I followed the traditional water bath canning method for tomatoes.  Boil mason jars for about 40 minutes and voila! you’ve got canned tomato sauce.But I was weary of the water bath. Why?  Tomato canning is a summer activity. It seemed like every time I canned it was about 95 degrees outside. Add a huge pot of boiling water and you’ve increased the heat and humidity in your already-sweltering house. With this summer’s heatwaves I didn’t know if I could bear another hot canning session.

That’s where pressure canning comes in. Pressure canning cuts the tomato processing time in half and you don’t have a boiling cauldron going for hours. Can you use a pressure cooker as a pressure canner? Unfortunately no. A pressure cooker is different from a pressure canner and cannot reach 240 degrees.  This temperature kills harmful bacteria and their toxin-producing spores.  Here is a link to my pressure canner from Amazon.

Preservation method: Pressure Canning

Difficulty level: Moderate

Tomato Sauce (Pressure Canned)

For a thin sauce, you’ll need about 35 lbs of tomatoes to produce seven quart jars.  For a thicker sauce, you’ll need about 45 lbs of tomatoes to produce seven quart jars.

Fresh tomatoes (I buy my tomatoes from Dolan Creek Farm and ask for a mix of different varieties)

Bottled lemon juice (bottled juice, versus fresh, guarantees the correct acidity that is needed for canning tomatoes)

Salt (optional)

  1. Fill a large saucepan halfway with water. Place jars in water. Bring almost to a simmer over medium heat. Keep jars hot until ready to use. You want them nice and hot when you fill them to prevent jar breakage.
  2. Prepare pressure canner by filling with water according to your manufacturer’s instructions.  Bring water to a simmer in canner and keep water at a simmer until filled jars are placed inside.
  3. Wash tomatoes and dip in boiling water for 30 to 60 seconds or until skins split. Place hot tomatoes on large sheet pan and continue boiling tomatoes until you fill the sheet pan.
  4. Move pan near sink and wearing big, brand-new, rubber kitchen gloves remove skins from tomatoes.  The gloves protect your hands from the hot tomatoes and also grip onto the tomato skins making peeling a snap.  I use a new set of kitchen gloves for every batch of tomatoes I can.
  5. Cut tomatoes in halves or quarters and remove pulpy seeds with gloved fingers. Place skinless tomatoes in large pot. When pot is 3/4 full, bring tomatoes to a boil and boil 5 minutes, uncovered, in large saucepan – mashing them a bit with a wooden spoon to break up the larger pieces.
  6. Meanwhile, add 1/2 tsp salt (optional) to each heated pint jar and one tablespoon bottled lemon juice. For quarts, 1 tsp salt (optional) and 2 tbsp. bottled lemon juice. Then fill heated jars with hot tomatoes, leaving 1-inch headspace. Use a long, wooden skewer to remove any air pockets and readjust to 1-inch headspace if necessary. Using a damp cloth, carefully wipe rims of jars and ensure there is no juice or tomato pulp on the rims which will prevent a proper seal. After cleaning jar rims, adjust two-piece caps to “fingertip tight”.
  7. Follow your pressure canning instructions.  Adjust water level, lock lid and bring to a boil at medium high heat.  Vent steam for 10 minutes, then close vent.  Continue to achieve 10 lbs pressure.  Process both pint and quart jars for 15 minutes.  It is important to maintain 10 lbs of pressure the entire time.  If the pressure dips below 10 lbs, bring pressure back up to 10 lbs and start your kitchen timer at zero again.
  8. Turn off heat source when processing is complete.  Let canner cool naturally. Do not remove the gauge. After canner reaches zero naturally wait five more minutes.  Remove gauge and unlock lid.  Remove jars from canner and set upright on kitchen towel. Leave jars undisturbed for 24 hours.
  9. Check lids for proper seals. Refrigerate any jars that have not sealed and use within one week.  Label and store sealed jars in a cool, dark place for up to 1 year.