Canning tomatoes? The very thought of canning anything causes me a little (ok more than a little) discomfort. Why you ask? I worry about eating something contaminated. What if I make a mistake and the food goes bad? Would I be able to tell?
To be honest, I’ve never canned anything… until now. My friend Valerie Tschaar offered to show me how easy it is to can tomatoes from the garden… using a pressure cooker. Now that sounds like a safe and sterile method to me.
While tomatoes are a high acid food and can be preserved using other methods, we’ve decided to use the pressure cooker. Some recipes for jams, jellies, pickles, etc. should be canned using the boiling water method.
Sit back, relax and see how easy it is to do.
What You Will Need
- Fresh Ripe Tomatoes
- Canning & Pickling Salt
- Bottled Lemon Juice
- White Vinegar
- Quart size wide mouth canning jars
- Lid (must be new) and band (can be reused)
- Pressure Cooker/Canner
I had several varieties of tomatoes in my garden and selected an assortment. We estimate it takes about a standard size colander filled with tomatoes to make enough processed tomatoes to fill two quart jars. Gently place the raw tomatoes into boiling water and let them cook for about a minute. Do not use aluminum pots or bowls. We used stainless steel. (The pressure cooker is aluminum, which is okay because is never comes in contact with any food – only the sealed jars are placed inside the cooker).
Remove from water and let them cool to touch
Remove them and let them cool down enough to handle, then grab a paring knife and a cutting board.
For this canning project, we used wide mouth quart size canning jars from Ball. We ran the jars through the dishwasher just prior to using them.
Whole, Chopped, Diced, Pureed – Your Choice
We canned the tomatoes uncooked and whole, packing them tight to remove air spaces. You could also dice, chop or puree them. Making tomato sauce is another option, provided you cook it down and let it thicken a bit. If you don’t you’ll end up with the bottom portion of your jar filled with liquid. It is your choice whether to add herbs, spices and flavorings before canning or pack them plain. Valerie had a good point saying she preferred to add fresh herbs and seasonings when she opens and uses the jars.
Add two tablespoons of lemon juice and one teaspon of canning salt.
Fill the jars with the tomatoes, pressing down to fill any air pockets. Use a knife to work out any bubbles. Add two tablespoons of bottled lemon juice and one teaspoon of salt. Clean the opening of the jar. Place the lid on the jar and screw on a band.
Sterilize lids in hot (not boiling) water. Place lids on top and screw on bands.
This pot is a 16 qt Presto cooker which is available on Amazon (Presto 1755 16-Quart Aluminum Pressure Cooker/Canner). It holds 7 quart jars. Fill it with 3 quarts of water and add 2 tablespoons of white vinegar. The vinegar prevents water stains on the outside of jars. We came up with a solution to keep the jars in place when you are canning less than seven jars. Simply use empty jars filled with water as place holders. This keeps the jars from bouncing around in the cooker.
When finished cooking, turn off the heat and let the cooker cool down. Follow the instructions for your cooker to determine when it is safe to open (once cooled down and pressure has been released). Remove jars carefully and place on heat safe counter to finish cooling.
Wait for the POP!
You’ll hear the jars make a POP sound as they cool with means they are sealed. You can tell by looking at the lid which will appear concaved (slopes downward in the center). You know this is the part I am watching very carefully.
A little liquid at the bottom of the jar is okay. We did a second batch a few days later and this time we pureed the tomatoes and cooked them for about 45 minutes. That eliminated most of the liquid at the bottom.
This was a fun project and was easier than I thought it would be. It is hard to grow tomatoes here during July and August in Houston. My plants look exhausted and spent already, especially with the drought and heat we are experiencing. Canning is a way to enjoy the harvest for the rest of year, long after the plants have finished producing.
For complete instructions and more helpful tips, visit Ball’s site Fresh Preserving.
Thanks for the information! I am more afraid of the pressure cooker than the canning. I guess everyone has a strange phobia or two
Jacqueline D'Elia says
Actually the pressure cooker is very easy to use and safe. But if it were to explode – that would be something to worry about! 🙂
Rooted in Atascocita says
It has been a while, but I have canned tomatoes before. Very worth the effort you have to put in to the process! Great pictures here!
Thanks for this post, Jackie! I will have tons of tomatoes at the end of the season and I’ve always wanted to can, but am a bit intimidated by the process. I have a pressure cooker and this is the perfect way to do it! Easy and safe. I will post on how mine turn out! Thank you again!
Wow! You did a fantastic job. You made the steps to canning very clear and detailed. I’m always striving for that on my cooking blog. Great photos, too. (Mine is seriously lacking in that department!) I’ve always wanted to learn to can, so maybe I can try now. I hope you pop over to my blog as well for some yummy recipes for those lovelies!
The last time we made and canned our own spaghetti sauce, we peeled the tomatoes the same way you did, then put them in the slow cooker for like 8 hours on low, stirring about once an hour. When it was starting to thicken up, we then added McCormick’s Spaghetti Sauce seasoning packet, and let stand for another hour. Then we gave it all a final stir, before filling the jars. It is important to note that the jars should already be hot before filling them.
Is there a difference between a regular pressure cooker and and canning pressure cooker?
hi, can we use another way to seal the jars beside the pressure cooker ? thank you
Jacqueline D'Elia says
Pressure canners work better for tomatoes and other low acid foods – you’ll get less spoilage with a pressure canner. I would not recommend it.
The USDA has a recipe for crushed tomatoes you can do in a BWB. https://nchfp.uga.edu/publications/usda/GUIDE%203%20Home%20Can.pdf