If you’ve had a good tomato harvest this year, turning those ripe beauties into homemade marinara sauce is a perfect way to preserve the flavors of summer. There’s nothing like making your own sauce from scratch—knowing exactly what went into it—and enjoying it for months to come. While canning your own marinara might seem like a huge undertaking, it’s incredibly rewarding to fill your pantry with jars of fresh, flavorful sauce that you can grab anytime you need.
In this post, I’m sharing the detailed process of how we turn our garden tomatoes into marinara, using a food mill, propane burners, and pressure canning for safe, long-term storage. Plus, I’ll explain why pressure canning is the best choice when you’re not working with a strictly measured recipe.
Ingredients and Equipment You’ll Need:
• Fresh or frozen tomatoes (we used frozen tomatoes from our garden that had been thawed)
• 1-2 tablespoons of sugar (optional, depending on how sweet or tart your tomatoes are)
• 2-3 tablespoons of minced garlic
• 1-2 tablespoons of Italian seasoning
• 1-2 medium onions, chopped
• 1-2 tablespoons of minced onion
• Fresh curled parsley, chopped (or other fresh herbs of your choice)
• Bottled lemon juice or citric acid (for safe canning)
• Food mill (for removing skins and seeds)
• Immersion blender (for blending the sauce smooth)
• Pressure canner (we used a Nesco digital pressure canner)
• Jars and lids (we used @ForJarsLids)
• Large cooking pots (we used lunch lady pots for big batches)
• Propane burner (optional, but perfect for outdoor cooking)
Step-by-Step Instructions
1. Start with Fresh or Frozen Tomatoes
We had a stash of tomatoes in the freezer from earlier in the season. Freezing tomatoes is a great option if you want to save them for processing later—it makes skinning them a breeze! Once thawed, the skins slip right off without any blanching needed. You can also drain any liquid off after thawing, as this is what would be boiled off anyways and will make the process go so much faster!
If you’re working with fresh tomatoes, be sure to wash them thoroughly and remove any stems or bad spots.
2. Remove Skins and Seeds Using a Food Mill
After thawing the tomatoes, we ran them through a food mill to remove the skins and seeds. The food mill makes quick work of this task and gives you a smooth, seedless tomato base to work with. Don’t worry if your tomatoes are a little watery—this will cook down as you boil the sauce.
3. Cook Down the Tomatoes
Transfer your milled tomatoes into a large pot. Since we were making a big batch, we used what I affectionately call “lunch lady pots”—large enough to hold gallons of sauce at once.
Cooking outside on propane burners is a game-changer for big batches like this. Propane burners run at higher BTUs than a typical kitchen stove, so they heat up fast and maintain a consistent boil. We simmered our tomatoes for about 3-4 hours to cook off some of the excess water and concentrate the flavor. The exact timing is up to you—if you like a thinner sauce, you can stop sooner, or cook longer for a thicker consistency. Just keep in mind that it will thicken more after canning.
4. Season Your Sauce
As your tomatoes boil down, you’ll want to start adding your seasonings. For our sauce, we used:
• 2-3 tablespoons of minced garlic
• 1-2 tablespoons of Italian seasoning
• 1-2 medium onions, chopped
• A few tablespoons of minced onions
• Fresh curled parsley from the garden
Feel free to adjust the seasonings to suit your taste! Some people like to add basil, oregano, or even a pinch of red pepper flakes for heat. We also added about 1-2 tablespoons of sugar to balance the acidity of the tomatoes. Depending on your tomatoes’ natural sweetness, this may be optional.
5. Blend the Sauce Smooth
Towards the end of the cooking time, use an immersion blender to puree the sauce until it’s smooth. If you like a chunky marinara, you can skip this step or only blend part of the sauce. For us, a smooth, velvety texture was the goal, and the immersion blender made it easy to get the perfect consistency right in the pot.
6. Acidify the Sauce for Safe Canning
One of the most important steps in this process is ensuring that your sauce is acidic enough for safe canning. While tomatoes are naturally acidic, the moment you start adding lower-acid ingredients like onions, garlic, and herbs, you reduce that acidity. To ensure that your sauce is safe for long-term storage, it’s crucial to add lemon juice or citric acid to each jar before canning.
How much to add:
• For pint jars: Add 1 tablespoon of bottled lemon juice or ¼ teaspoon of citric acid.
• For quart jars: Add 2 tablespoons of bottled lemon juice or ½ teaspoon of citric acid.
This step helps create an acidic environment that prevents the growth of harmful bacteria, especially Clostridium botulinum, which can cause botulism.
7. Why I Chose Pressure Canning Over Water Bath Canning
Many people ask if they can water bath can their marinara sauce. While this can be done with strictly measured recipes that maintain high acidity, I didn’t want to take any chances. Because I wasn’t precisely measuring my ingredients, I couldn’t guarantee the exact pH of my sauce. And when in doubt, pressure canning is the safer option.
Why pressure canning?
Water bath canning is only safe for high-acid foods (pH 4.6 or lower). If the acidity of your food is uncertain, it’s best to use a pressure canner, which reaches much higher temperatures (over 240°F) to kill off any bacteria, including the spores that cause botulism.
By pressure canning the sauce, I could safely preserve my homemade recipe, even without strict measurements. Pressure canning is my go-to for anything that involves low-acid ingredients or any recipe I’m modifying on the fly.
8. Canning the Sauce
Now that your sauce is ready, it’s time to can! Here’s how to safely process your jars:
• Prepare your jars and lids: Wash your jars and lids (I use @ForJarsLids for a reliable seal) and keep them warm until ready to use.
• Fill the jars: Carefully ladle the hot sauce into the jars, leaving about 1 inch of headspace. Be sure to add your lemon juice or citric acid to each jar before sealing!
• Seal the jars: Wipe the rims of the jars with a damp cloth to remove any sauce that could prevent a proper seal. Place the lids on and secure with rings, tightening them to fingertip tightness.
• Pressure can the jars: Follow the instructions for your specific pressure canner. We used a Nesco digital pressure canner, which made the process straightforward. Process the jars at 10-11 PSI (adjusting for your altitude) for 20-25 minutes for pint jars. For quarts, the time will be slightly longer.
• Let the jars cool: Once processing is complete, allow the pressure canner to cool naturally before opening. Remove the jars and let them sit on a towel, undisturbed, until fully cooled. As they cool, you should hear the satisfying “pop” of the lids sealing.
9. Storing Your Marinara Sauce
Once the jars are sealed and cooled, check the lids to ensure a tight seal. Any jars that didn’t seal properly should be refrigerated and used within a week, while the sealed jars can be stored in your pantry for up to a year.
Now, you have jars of rich, flavorful marinara sauce ready to use in your favorite dishes, from pasta to pizza to lasagna!
Final Thoughts on Homemade Marinara and Pressure Canning
There’s something truly satisfying about making your own sauce from tomatoes you’ve grown and preserved yourself. This recipe captures the essence of summer and ensures that you have a stock of wholesome, homemade marinara to enjoy all year long.
If you’re ever unsure about the acidity level of your sauce or are working with a recipe that hasn’t been tested for water bath canning, always opt for pressure canning. It’s a foolproof way to safely preserve your sauce and avoid any potential risks.
Happy canning, and enjoy the fruits of your labor! 🍅
What’s your favorite way to use homemade marinara sauce? Drop your tips or recipes in the comments below!
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