Canning Tomatoes: A Step by Step Guide

Canning tomatoes is easier than you think and even beginners can do it. Tomato plants always seem to grow more tomatoes that people can eat during the summer months. The perfect solution for this is to try canning tomatoes! This allows you to enjoy the fruits of your labor for months. You can also buy fresh tomatoes from a farmers market or local farm stand. If you want to see the process from start to finish, I have an entire video on my YouTube Channel, and you can follow along with the steps in the blog below.

Safety Guidelines for Home Canning

It is incredibly important to follow safe canning guidelines from National Center of Home Food Preservation (NCHFP) and Ball canning recipes. Another place to find local resources is your local canning extension office which is normally run through a local college. You can google, “local canning extension” and it will show you what is in your area. Local grange halls often have canning classes if you know that you will learn better in person. It is important to never follow rebel canning recipes for tomatoes. Just because your neighbor's grandma used to do it one way, does not mean that it is safe. The acidity in our produce has changed over time and the tomatoes that our grandmas canned are not the same ones that we have available to us. You should always follow safe canning practices so that you know what you are feeding your family is safe.

How To Wash Tomatoes

In order to get started canning tomatoes, the first thing that you should do is wash your tomatoes. I do this whether they are tomatoes that I picked from my garden or ones that I got from a farmers market or the supermarket. I wash my tomatoes in a large bowl with ¼ cup 5% distilled white vinegar and 10 cups of water. Allow them to soak for 2 minutes before rinsing. This kills any mold spores and other harmful pathogens on the tomatoes. I wash many of my produce items this way and if you want to learn more about washing produce, you can find instructions for how to wash and store 75 produce items in my bestselling series, I Bought It Now What.

Canning Tomatoes: How To

I can my tomatoes as diced tomatoes because I have found they are the ones that I will use the most often in recipes. Once all of the tomatoes are washed, I core them and cut an X on the bottom. I place them in boiling water for 30 seconds and then remove them from the water with a tool called a spider strainer. After removing the tomatoes, put them into an ice bath and remove the skins. At that point, they are ready to be diced into the desired size.

Filling the Jars with Tomatoes

I sterilize my jars by boiling them in water for 10 minutes. This should always be done prior to water bath canning.

After dicing the tomatoes and sterilizing the jars, it is time to fill the jars. I prefer a quart sized jar and you can use either a wide mouth or regular. I try to save all of the juice from the tomatoes so that I can put that in the jars with the diced tomatoes. I fill the jars and add 2 tablespoons of commercially canned lemon juice per quart sized jar. Then I use a debubbler to push down on the tomatoes and remove any bubbles in the jars to prevent botulism. When filling the jars, there should be ½ inch of headspace in the top of the jars.

Once the jars are filled and measured, use a paper towel with vinegar to wipe the top of the jar to remove any tomato juice or debris left on the jars. Now it’s time to place the brand new lids on the cans and add the ring so that it is finger tight. This means that you will tighten them gently with your fingers, do not try to make them excessively tight because this will cause them to not remain shelf stable.

Water Bath Canning

Use a jar lifter to move your jars of tomatoes into the pot of boiling water. This is the water bath canning method. Water bath canning can be used for tomatoes and the processing time is 45 minutes for quarts and 40 minutes for pints. If you live at a higher elevation, be sure to check if your times need to be adjusted in order to safely can your tomatoes. I used a large stock pot for my water bath canning process. It has a trivet at the bottom to hold the jars and it has to have space for at least 1 inch of water on top of the jars. If you do not have enough jars to fill the pot, use extra empty jars to prevent any from tipping over and breaking during the canning process.

After the tomatoes have been in the water for the required amount of time, I will let the water begin to cool and allow the jars to acclimate to the room temperature. After 24 hours the rings should be removed in order to prevent a false seal. I date my jars, clean the outside, and then they are ready to go into my pantry. These canned tomatoes will be shelf stable for about three years!