Preserve the Harvest: How to Can Tomatoes at Home

If you frequently use canned tomatoes in cooking, consider learning how to can tomatoes at home! It’s a great way to save the summertime harvest and help you eat locally year round. Once you understand the “how-to” aspect, check out the recipes for canning tomatoes below!

We’ll start with how to can tomatoes safely, something that beginners should definitely take the time to read. I talk about what exactly that means below, as well as answering some common questions. If you’re new to canning, go here to learn more about canning equipment and what you’ll need. 

lots of tomatoes in a galvanized tray


How to can tomatoes: A beginner’s guide

Fresh, homegrown tomatoes can easily be preserved as a single-ingredient item to be used in cooking some of your favorite recipes. The home canned alternative can replace the canned tomatoes that you pick up at the supermarket for adding to homemade chili or butter chicken.

They can also be preserved as a ready-to-use product, such as salsa, pizza sauce, or chutney. [Scroll down for a collection of recipes.]

No matter how you prefer to preserve them, know that it’s an endeavor that is well worth your time. The fresh flavor of home canned produce outshines the store bought alternatives, plus you’ll know exactly where the tomatoes came from.

What are the best tomatoes for canning?

While any tomato can be preserved using the methods described here, Roma tomatoes are meaty and less watery than slicing tomatoes, making them a great choice for a thick and rich tomato sauce.

The famous Italian San Marzano tomatoes are a Roma variety that is commonly used for canned tomato products. 

canned salsa, from above

What is the best way to preserve tomatoes?

When it comes to canning tomatoes, water bath canning is really the easiest method for preserving them for the pantry. 

  • The lower temperature with water bath canning assures that the fruit will retain some of its texture. 

How long do you water bath tomatoes?

The processing time depends entirely on the individual recipe you are using and the size of the jars you’re processing.

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🍅 Safety First!

Canning is an excellent way to preserve food for the pantry, but there are some important safety considerations to keep in mind. The recipes on this site have been made following safe canning procedures by a certified Master Food Preserver.

  • Know the difference between water bath canning and pressure canning. Low acid items must be pressure canned for safety. 
  • Altering ingredients may change the recipe’s pH, posing a safety issue. I highly recommend investing in pH paper to test your products for acidity level when canning. Note: The Hawaii Master Food Preservers suggest a pH of 4.2 or lower in the tropics. In other regions, the recommended pH is 4.6 or lower.
  • Use the proper jars and lids. Never reuse lids, with the exception of the Tattler or Harvest Right hard plastic lids that are intended for such a purpose.
  • For more on canning equipment, please go here
canning jar full of crushed tomatoes

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Can I add vegetables to canned tomatoes?

If you are using a safe canning recipe from a trusted source that includes the addition of vegetables, then yes, you can. But adding vegetables that are not specifically called for in the recipe is not recommended.

Here’s why:

  1. Most vegetables are low in acid and are not safe for water bath canning. Adding them to a recipe for canned tomatoes can alter the pH of the recipe. If the pH is too low, botulism spores can thrive in the sealed jars.
  2. Adding vegetables may impede heat penetration. When processing jars in a water bath, the contents need to reach a specific temperature for a specified amount of time, as spelled out in the recipe. Pieces of vegetable mixed in with the tomatoes may not be heated completely through in the recommended amount of time. 
lemon with a twist of peel.

Do you have to add lemon juice when canning tomatoes?

This is the million dollar question! Certainly lemon juice is not the only way to acidify your product. Vinegar and citric acid are other acceptable options, though the vinegar may alter the flavor. 

A more important question is perhaps WHY would you have to acidify tomatoes? This has to do with reaching the necessary pH for safely processing tomatoes in a water bath canner

Clostridium botulinum, commonly known as botulism, cannot survive in acidic conditions. Processing acidic foods in a boiling water bath controls the potential growth of mold, yeast, and bacteria. 

A wide variety of tomatoes grown in home gardens and available at market means that the pH of the fruit themselves can vary greatly. Very ripe ones may also have a higher pH, meaning that ripeness plays a factor as well. We can’t assume that all tomatoes are acidic enough to process safely in a water bath without adding additional acid. Adding items like onion or pepper may require the addition of acid.

canning jar with tomatoes.

Acidifying Tomatoes

When canning whole, crushed, or juiced tomatoes, the recommended addition of acid according to the National Center for Home Food Preservation is:

Per pint

    • 1 tablespoon of bottled lemon juice
    • ¼ teaspoon citric acid
    • 2 tablespoons vinegar (5% acidity)

Per quart

    • 2 tablespoons of bottled lemon juice
    • ½ teaspoon citric acid
    • 4 tablespoons vinegar (5% acidity)
hand putting chunk of tomato in a jar

How to check pH and when to add acid

Now, all that being said, if you’d prefer to avoid adding an acidifying agent, you can test the pH of the tomatoes themselves using a pH tester or pH paper.

If the tomatoes are a pH of 4.6 or lower it is safe to can them without the addition of an acid. Do not do this without testing the pH! If you’re not able to test the pH, do NOT deviate from the instructions in a safe canning recipe. 

Note: The Hawaii Master Food Preservers suggest a pH of 4.2 or lower in the tropics. 

Acidifying the tomatoes to a safe pH allows you to use a water bath canner and is how you can tomatoes without pressure cooker. If you don’t have the equipment to check the pH, always add the recommended amount of acid.

To check pH, prepare the tomatoes and use a strip of pH paper to test the product. 

Order this pack of pH paper and keep it on hand to check for safe acidity levels when canning. Less than $10 for peace of mind!

If the pH is 4.6 or lower (4.2 in the tropics), it is safe to can. If it’s higher, add acid as recommended above or until you achieve the necessary pH level. I always stay well under this marker for absolute safety and prefer my canning projects to fall under a pH of 4.0.

Pressure Canning

Pressure canning is perfectly fine, but larger chunks will cook down substantially in the high heat of pressure canners, becoming more like mush. This is fine for items like sauce, but if you’re trying to retain the shape or texture of the fruit, you’d be best to stick with water bath canning.

  • Using a pressure canner to preserve tomatoes can ultimately take a bit less time.
  • Don’t eliminate the acidifier called for in the recipe though. 
wedges of fresh tomato on a cutting board

Do you have to cook tomatoes before canning?

No. You can raw pack or hot pack tomatoes. This will depend on your recipe and the processing time for each will vary. 

As you’d imagine, raw packing is when you fill canning jars with fresh, raw produce. This recipe for canning crushed tomatoes is a raw pack recipe (and crazy easy!). Start with whole tomatoes, cut into chunks small enough to fit into your jar, and pack into jars. 

Hot packing produce means the product is cooked first and transferred to canning jars while still hot. 

tomato with peel shriveling off it

Do you have to peel them?

It is recommended in the USDA Complete Guide to Home Canning that you do. (The guide is available as a free download at that link.)

Here’s why: Clostridium botulinum spores, commonly known as botulism, live in the soil and are commonly found on the surface of fresh foods. Washing produce removes some of those spores, as does blanching. Peeling removes more.

But here’s the other thing. These spores only grow into dangerous toxins in the absence of air or in low-acid environments, though. Botulism cannot survive in acidic conditions. Tomato products properly acidified for water bath canning don’t provide the necessary environment for those botulism spores, but low acid tomato recipes that call for pressure canning do. This is why we acidify tomatoes.

Some people feel that the skins can impart a slight bitter flavor, but for me itʻs more of a textural issue. (Large pieces of the skin tend to roll up into tight little sticks when cooked.) Here are more details on how to easily peel tomatoes.

I tend to peel them when canning whole tomatoes or large chunks, but if I’m making salsa I don’t. Instead, I chop the fruit in a food processor and and the smaller pieces of skin are not at all noticeable. 

Of course you’ll want to consider the source of your tomatoes. If they’re from your garden and free of toxic pesticides, you’ll likely feel safe using the fruit skin and all. Commercially produced crops that are sprayed with harsh pesticides might make you think twice about eating the skin.

beautiful tomatoes in a wooden bowl

15+ Recipes for canning tomatoes

Just about any tomato product you purchase at the grocery store can be made safely at home, so long as you use the appropriate canning recipe and safe canning methods.

Take note, beginners! Choose safe recipes and follow them exactly. Canning is not the time to experiment!

Properly acidified recipes can be safely canned in a water bath canner. Those that have meat added to the recipe, such as a spaghetti sauce, MUST be processed in a pressure canner

multiple canning jars of salsa

Canning Salsa

One of my favorite ways to preserve an abundant crop? Salsa! It’s endlessly versatile, and can simply be served with chips as a snack, or used as an ingredient in making soups and chili. 

chutney served on sliced baguette bread

Tomato Chutney

For a deliciously sweet and savory recipe for canning tomatoes, give chutney a try. It’s one of those recipes that is simple to make, but nice enough for company. These are hot pack recipes that requires cooking the chutney before bottling it.

jars of home canned pizza sauce

Pizza Sauce

If you’re like my family, homemade pizza is on the menu regularly. I’ve been making my own pizza sauce when tomatoes are available for years. I love having lots in the pantry for whenever we decide pizza is a good idea! 

jars of red jam, one with lid off

Tomato Jam

A bit like a chunky ketchup, this jam is sweet with the light flavor of tomatoes. Try it in a BLT sandwich!

Taco and Hot Sauce

Add a little flavor to your favorite Mexican meals with this taco sauce recipe. This one works well with meaty Romas. 

Spaghetti Sauce

Having a pantry stocked with ready-made spaghetti sauce can help a busy person get dinner on the table in a hurry. Knowing those jars were made from fresh, locally grown tomatoes will make it taste that much sweeter!

4 canning jars full of crushed tomatoes

Raw-Packed Tomatoes

If you like to use tomatoes in your cooking, this recipe for raw-packing is one of the easiest ways to preserve the fruit. Peel it, cut it into chunks, add salt and acid, then press into jars. 

Home Canned Tomato Sauce

You can replace the canned sauce you buy at the store by making your own at home. 

DIY Tomato Paste

Making paste requires reducing the volume of paste tomatoes by half and removing the skins and seeds with a food mill or chinois to make a smooth and flavorful concentrate that you can use in cooking. [More on using a food mill here.]

Canning Juice

If you prefer to drink your harvest (bloody Mary, anyone??) homemade tomato juice might be just the thing for your pantry. 

green tomato relish in a square white dish on a red striped background

Canning Green Tomatoes

While red, ripe fruit is most familiar, using the green fruit left on the vine at the end of the season is a great way to avoid waste. From pickles to relishes, these recipes make the most of the crop! 

jar of canned tomatoes
Do you have more questions about home canning? First time canner? Check out this list of 101 frequently asked canning questions!

Originally published in July 2021; this post has been updated.

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About the author: Kris Bordessa is an award-winning National Geographic author and a certified Master Food Preserver. If you want to send Kris a quick message, you can get in touch here.

4 comments… add one
  • Lolita Roibal Aug 30, 2021 @ 7:24

    Thanks so much for all of the info! I made some of your salsa from my garden tomatoes and it was a big hit! I started to read up more on your info regarding testing the pH and I was wondering if it’s possible to test the pH AFTER the batch is made? I was thinking I’d like to test my salsa the next time I open a jar. But next time I will definitely follow your advice regarding testing prior to canning!

    • Kris Bordessa Sep 12, 2021 @ 8:42

      You can certainly test the jar after you open it, but yes, GOOD IDEA to do it prior to canning.

  • Chuck Jul 6, 2021 @ 13:13

    Great article with very concise directions and information. In the northern Rockies we are still about 2-3 months out for tomato season. Thank you!

    • Kris Bordessa Jul 6, 2021 @ 16:29

      Glad you found it useful!

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