Transform fresh from the garden tomatoes into a delicious Crock-Pot Tomato Sauce in this yummy recipe that is perfect for canning in jars!

Slow Cooker Tomato Sauce
At our local church we had what we called a “Salad and Swap”. Everyone brought 5 things they no longer needed, and then we got to try for 5 of those things. Well one of those things I ended up “winning” was a big box of Amish Paste Tomatoes. Yum!
So, within about 36 hours I was ready to get those beautiful tomatoes canned. I normally can whole tomatoes. This time I decided that it would be good to can up tomato sauce to use in chili and soups.
It turned out great, they all sealed and we’ve already used one up in a chili recipe I made.
About Canning Supplies
If you are new to canning food for long term food storage I suggest that you purchase a copy of what many consider the “bible” of canning books… The Ball Blue Book. This book will have all the information on how to safely can your food. With instructions on how to both use the water bath method and pressure canning. This book will also give you all the tips you need on times to process everything, adjustments you need in your canning time if you live at higher elevations, etc.
For canning tomatoes and tomato sauce you can use a water bath canner or a steam canner. And if you are going to can anything that is considered a low acid food like meat, beans, corn, and most vegetables then you will want to invest in a pressure canner.
You will also need canning jars in whatever size you want based on how you use your crock-pot tomato sauce. I tend to use tomato sauce in 8 ounce or 16 ounce increments so I stick to those sized jars. If you buy new canning jars your jars will come with new lids and rings. If you are reusing older jars you will need to buy new canning lids and rings.
Lastly, most canners start with a basic canning tool set that includes a jar lifter, canning funnel and bubble remover. Some kits come with all sorts of other bits and bobs, but to be fair, you probably wont use most of that stuff. And if you need something else it is best to purchase it individually so you don’t end up with a bunch of kitchen clutter!

Frequently Asked Questions
Tomatoes contain a lot of water and before they can become sauce you need to cook them down quite a bit to allow the naturally occurring water to cook off. Using your slow cooker allows you to cook that water off without having to worry about your sauce burning and having to monitor a pan on the stove-top. You can literally walk away at this point in the cooking time and just let the slow cooker do it’s thing.
Tomato sauce really should be pretty pain. Adding a bunch of spices and herbs to you sauce takes the sauce into the marinara sauce line pretty quickly. Although I have found that if you cook a lot of Italian style food that adding one or two whole fresh basil leaves to the jar before ladling in the tomato sauce adds a nice flavor.
One tip many gardeners face is an onslaught of fresh tomatoes and no time or desire to can up their tomatoes in the heat of summer. So they wash and core their tomatoes and toss them whole into freezer bags and stash them in the freezer until they have enough tomatoes, the weather has cooled off a bit and they have more time. And that is when they can up their homegrown tomatoes.
This recipe will indeed work with frozen tomatoes. Just keep in mind that when you freeze fruits (and tomatoes are a fruit) that as they thaw they will release a lot of water. Strain that water off and then proceed to cook the tomatoes as normal. Freezing and thawing the tomatoes and then straining off the water may actually shorten the time you need to cook the tomatoes.

More Recipes To Love!
Crock-Pot Roasted Cherry Tomato Sauce
This easy recipe for Slow Cooker Roasted Cherry Tomato Sauce features fresh seasonal cherry tomatoes and just a few simple ingredients for an amazing sauce!
Crock-Pot Pizza Sauce (Canning Version)
Use up your garden or local farmer's market tomatoes to make up a batch of fresh Slow Cooker Pizza Sauce which you can then choose to can or freeze for long term storage!
Crock-Pot Pizza Sauce
Let your slow cooker do all the work in making this simple pizza sauce to use for homemade pizza or other creations.
Crock-Pot Strawberry Jam
This amazing bright & fresh recipe for Slow Cooker Strawberry Jam is super easy and a great beginner recipe for anyone new to canning.
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This recipe for Crock-Pot Tomato Sauce is Weight Watchers Friendly on the new Personal Points plan. You can see the WW personal points for this recipe here on the Weight Watchers website. Click here for MORE of our Weight Watchers Recipes

Crock-Pot Tomato Sauce Recipe
Equipment
- Pint Sized Canning Jars or Quart Sized Canning Jars (with lids)
Ingredients
- 4 Pounds Fresh Tomatoes (After De-Seeding)
- 15 Ounces Bottled Lemon Juice
Instructions
- Cut the stem off each tomato, cut into quarters and then cut out as much of the seeds and excess juice as possible.
- Place prepared tomatoes in the bottom of a 6 quart or larger slow cooker.
- Cover and cook on LOW for 2 hours, stirring occasionally.
- Using a slotted spoon, spoon the cooked tomatoes into the jar of a blender, leaving behind any excess liquid. (Dump out and discard any liquid from the slow cooker).
- Pulse the tomatoes in the blender a few times until you reach a puree.
- Add puree back into slow cooker and continue cooking, uncovered, until the sauce is as thick or as thin as you want it. I cooked mine for an additional 8 hours.
- Add 1 tablespoon on lemon juice to each cleaned and sterilized pint sized jar OR 2 tablespoons to each quart sized jar.
- Ladle tomato sauce into jars using a canning funnel to prevent spilling, leaving 1/2 inch of head-space.
- Use a plastic utensil or tool to place into the jar, to help the air bubbles to escape.
- Wipe off the top of each jar with a wet towel to wipe away any spillage.
- Place clean and new canning lids on each jar and screw on the rings until just finger-tight.
- Place the jars in warm water in a water bath canner on the stove-top.
- Turn the heat up under the water bath canning pot and allow the water to come to a full rolling boil. Place lid on the pot.
- For pint sized jars, process the jars for 35 minutes or 40 minutes for quart sized jars. Adjust the time accordingly if you are at an elevation above sea level.
- Times are quite uniform for tomato sauce, you just need to know your elevation.
Notes
Nutrition

Have you done this with frozen tomatoes? I froze some and so far I haven’t decided how I want to use them. Sauce sounds like a great idea.
I think frozen is fine, you’ll just have to watch the water content..and possibly drain it a bit, if it has too much water.
This recipe looks tasty. I have canned frozen tomatoes before. I freeze them when I have too many tomatoes to preserve by canning at the end of summer and then I can them later.
My mom has a glass top stove and we had no troubles at all getting our water bath pot to a rolling boil when we canned applesauce this past fall….
I have canned for years on my glass top and never had any problem ever.
I know some folks have had issues with it, but not everyone. Best to consult the owners manual for your particular stove-top to make sure the glass can handle the heat and weight of a big pot filled with water and jars.
Instead of getting house hit & steamy, my Husband used the burner for his fish/turkey fryer. Canning pot fits great. No steamy house or mess! I am new to canning even though my Mom canned for years before her passing. I wish I had pad more attention back then. What I wouldn’t give to have her here teaching me now! Thanks for the great recipes & tips.
Yes canning outdoors is awesome!
Can I used canned tomatoes.?
Hi Stacy, while this recipe has not been tested using canned tomatoes I don’t see why it wouldn’t work. If you give a try be sure to come back and let us know how it turned out for you!
Of I add dried herbs can I still water bath my sauce?
Yes you can Jennifer. Great question!
Any secrets on how to thicken the sauce? I cant tomatoes that are peeled and deseeded but still needs to be cooked down to a sauce. Would love to try this in the crockpot but want it on the thicker side.
Hi Traci, I would just suggest cooking longer with the lid propped up to allow the extra liquid in your tomatoes to evaporate and thicken.