Easy Canned Tomatoes

For those nervous about canning, tomatoes are a great place to start for a few reasons. Firstly, they can be raw-packed, meaning placed raw directly in jars. Secondly, owing to how long they get processed in the canner, the jars do not need to go through the added step of being sterilized. 

This recipe is an even quicker and easier version than ones you may have learned about, with no skinning of tomatoes required. This can help you can get more tomatoes put away for use in the colder months. 

That is terrific, since tomatoes can go into so many dishes, including soups, stews, spaghetti sauce, and ketchup, to name a few. Saving money too during the colder winter months when fresh vegetables are not nearly as affordable.

All of this is great news, if you want to minimize time spent in the kitchen and maximize time spent relaxing and enjoying the precious summer months we have in colder climates.

Just a word of caution. Take a moment to read through all the steps outlined below so that the process will go smoothly and your work will not be wasted. Saving you time and money.

Step 1: Organize Your Equipment

Gather the following equipment so that you do not end up starting the canning process, only to find you are missing something crucial:

• Water bath canner

• Mason jars sized 500 mL (one pint) or, at the most, 1 L (one quart), as well as coated metal lids and screw bands that are sized to fit your jars

• Canning tongs

• Knife (ideally small carving knife for coring to waste less of your tomatoes)

• Cutting board

• Funnel (ideally metal, so acid in the tomatoes does not corrode plastic into your food.)

• Clean tea towel and dishcloth

Step 2: Prepare your Jars and Other Equipment

Ensuring your equipment is clean is critical to helping create the sterile environment your food will need to stay fresh once canned.

1. Begin by thoroughly washing your equipment, including your jars, lids, and screw bands. Ensure it is clean and free of food and other debris, make sure your jars do not have any chips or breaks.
   
   

2. And…Voila. You are done cleaning. Why exactly? Because when you process your tomatoes for as long as outlined below in this recipe, it is no longer considered necessary to sterilize your jars prior to canning.[1]

Step 3: Gather Your Ingredients

Here is another reason why canning tomatoes is easy. You only need a couple of ingredients, namely:

• Tomatoes*

• Bottled or fresh lemon juice

*Roma tomatoes work well, because they are less watery. However, feel free to work with what you have.

Step 4: Prepare for Processing

To prepare your ingredients, simply:

1. Heat (but not boil) your jars for 10 minutes prior to filling to prevent them from getting thermal shock (see Step 5 - Processing, for instructions on how to best heat your jars).[2]
   
   

2. Wash tomatoes to remove dirt and debris, as well as pesticides (unless you are fortunate enough to have grown or gotten organic tomatoes). Remove cores and any bruised or unripe parts.
   
   

3. Quarter the tomatoes, or leave them whole or in halves. Whatever you prefer. (Just think about how you will be using them later, and prepare them the way that will work best for that.)
   
   

4. Add 1 Tbsp lemon juice per jar for 500 mL (pint) sized jars (double that if they are 1 L/quart sized). A word of caution: Use jars no larger than 1 L for this recipe.
   
   

5. Pack raw tomatoes into jars to within 1/2 inch (1 cm) of space left at the top of each jar. Press tomatoes into the jars with a spoon, so air pockets are removed. Add more tomatoes if needed to ensure that 1/2 inch (1 cm) of headspace is left in each jar.
   
   

6. Wipe jar rims. Centre lids on jars. Screw on the screw bands until resistance is met, then tighten more until they are fingertip-tight.

Step 5: Processing

Once you have packed your cans with tomatoes, you are ready for the final step of processing (which in canning terms means cooking and sealing) your canned tomatoes. To do this:

1. Place jars upright in the rack of a water bath canner, and completely submerge them in water. Putting them on an elevated metal rack will help prevent them from jiggling and breaking.
   
   

2. Put on the canner lid and bring the water to 100 °C (roughly to a boil, although altitude can affect boiling point, so be sure to use a thermometer). Cook the jarred tomatoes at a rolling boil for 85 minutes.[3]

Step 6: Cool Down

After you are done processing your cans, the heat is off (pun intended!) and you are ready for the cool down period. To do so, simply:

1. Turn off the burner and remove the canner lid.
   
   

2. Wait ten minutes.
   
   

3. Carefully remove jars from the pot, using canning tongs and oven mitts to avoid burns. Place them on a tea towel to absorb water.
   
   

4. Cool the jars (ideally for 24 hours to allow jars to properly seal) before moving and storing them. (You can move them shortly after they have been removed from the canner to a better location for cooling, if you wish.)

Step 7: Double Check Your Seals

At last. Your jars have been cooked and cooled down. The only thing that remains is to check the jar lids to ensure they have fully sealed, and act accordingly. To do so:

1. Check which jars have an indented lid, as sealed lids will curve downward. If you are unsure, press down on the centre of the lid.
   
   

2. If you are still unsure, grab the edges of the lid and pull the jar up while holding the jar with your other hand. If the lid does not come off, it is sealed.
   
   

3. Store any unsealed jars in the refrigerator or, possibly better yet, use the jarred tomatoes immediately.

The Fruits of Your Labour

There you have it. Once you are done, you can enjoy quite literally the “fruits” (as tomatoes are, of course, a fruit) of your labour! We hope you enjoy your easy canned tomatoes.

Researched, written and tested by Alisa McClurg, KW Urban Harvester volunteer.

Footnotes

[1] To be precise, one need not sterilize jars that are processed for more than 10 minutes. This is based on several sources, including the Bernardin Complete Book of Home Preserving (2024, p. 417) and The Complete Book of Small-Batch Preserving (2007, pp. 14-5), as well as the National Center for Home Food Preservation, the Government of Manitoba, Mississippi State University, Utah State University, Healthy Canning, and Simply Canning.

[2] Bernardin Complete Book of Home Preserving (2024, p. 417).

[3] As recommended by the Bernardin Complete Book of Home Preserving (2024, p. 356).