Slow Cooker Spaghetti Sauce

$4.40 recipe / $0.63 per cup
by Beth - Budget Bytes
4.88 from 47 votes
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I’ve made a few variations of pasta sauce over the years, but this Slow Cooker Spaghetti Sauce is definitely one of my favorites. The long slow simmer caramelizes the sugars in the tomatoes and creates a depth of flavor that can’t be matched. Plus, what more could you ask for than to just throw some ingredients in a pot, forget about it for 8 hours, and then come back to a rich, delicious homemade sauce? Then you can divide the sauce into portions, freeze, and you’ll have delicious homemade pasta sauce on hand for quick busy weeknight dinners.

Pasta sauce in a slow cooker with a spoon, garnished with parsley

Why make Homemade Spaghetti Sauce?

Pasta sauce can be bought premade really cheaply, so I think in a lot of cases it does make sense to just buy a jar and go with it. But if you want to have a little more control over the quality and ingredients of your pasta sauce while still keeping costs low, this Slow Cooker Spaghetti Sauce is a great option. 

What Size Slow Cooker to Use

This recipe makes about 2 quarts of sauce, so I would suggest using a 3 quart or larger slow cooker. You don’t need anything fancy, just a very basic slow cooker with basic functions like warm, low, and high. I do find that slow cookers made with a thick ceramic insert (or “crock”) cook much more evenly than metal inserts, like you’d have when using the slow cooker function on an Instant Pot.

Why Add Balsamic Vinegar?

The balsamic vinegar in this recipe adds a subtle depth and brightness to the sauce. It can seem strong at first, but it mellows out as the sauce is cooked. If you’re not a fan of balsamic vinegar or just don’t have any on hand, this recipe will still make a really amazing sauce even if you leave it out.

Can I Add Meat?

I’ve tried this sauce before with ground beef and I found the cook time to be far too long for the ground beef, so if you do want to add meat I suggest browning it separately and then just stirring it into the sauce after cooking. You can also check out my quick Weeknight Pasta Sauce for an easy and flavorful meat sauce option.

How to Freeze Pasta Sauce

This recipe makes about 7 cups. I suggest dividing the sauce into two or three cup portions before freezing so you can take out just enough for one recipe at a time to thaw. Let the spaghetti sauce cool completely in the fridge, then transfer to freezer-safe containers to freeze. The sauce will stay good in the freezer for about three months, but this can vary depending on the conditions in your freezer. If you use quart-sized freezer bags and freeze them laying flat they stack nicely in the freezer without taking up much space. 

You can thaw the sauce in the refrigerator overnight or just cut the bag away from the frozen sauce, place it in a saucepot, and heat over medium-low until it’s heated through (stir occasionally).

This sauce goes great with Homemade Meatballs (also freezer-friendly)!

A plate of pasta covered in sauce with bread on the side

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Slow Cooker Spaghetti Sauce

4.88 from 47 votes
Let the slow cooker do all the work for you when you make this big batch of freezer-friendly homemade spaghetti sauce.
Pasta sauce in a slow cooker garnished with parsley
Servings 7 cups
Prep 10 minutes
Cook 4 hours
Total 4 hours 10 minutes


  • 1 yellow onion ($0.32)
  • 4 cloves garlic ($0.32)
  • 2 28oz. cans crushed tomatoes ($2.00)
  • 1 6oz. can tomato paste ($0.69)
  • 1 Tbsp dried basil ($0.30)
  • 1.5 tsp dried oregano ($0.15)
  • 1 Tbsp brown sugar ($0.03)
  • 1 Tbsp balsamic vinegar ($0.14)
  • 4 Tbsp butter ($0.40)
  • 1 tsp salt (or to taste) ($0.05)


  • Dice the onion and mince the garlic. Place both in a 3 quart or larger slow cooker.
  • Add the crushed tomatoes, tomato paste, basil, oregano, brown sugar, balsamic vinegar, and butter to the slow cooker. Stir everything together well.
  • Place the lid on the slow cooker and cook on high for four hours or low for eight hours.
  • After cooking, give it a good stir, then add salt to taste. Start with just ½ tsp of salt and add more if needed (I added 1 tsp). Use the sauce immediately, refrigerate, or freeze for later.

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Serving: 1cupCalories: 77kcalCarbohydrates: 5gProtein: 1gFat: 7gSodium: 393mgFiber: 1g
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Homemade pasta sauce being spooned over a plate of spaghetti

How to Make Slow Cooker Spaghetti Sauce – Step By Step Photos

Onion and garlic in slow cooker

Dice one yellow onion and mince four cloves of garlic. Add both to a 3 quart or larger slow cooker.

Tomatoes added to slow cooker

Add 2 28oz. cans of crushed tomatoes and one 6oz. can of tomato paste to the slow cooker.

Seasonings added to the slow cooker

Also add 1 Tbsp dried basil, 1.5 tsp dried oregano, 1 Tbsp brown sugar, 1 Tbsp balsamic vinegar, and 4 Tbsp butter to the slow cooker. 

Sauce ingredients being stirred together before cooking

Give the ingredients a good stir until they’re evenly incorporated.

Simmered pasta sauce in the slow cooker

Place the lid on the slow cooker and cook on high for four hours or low for eight hours. After cooking, it will look a little like the photo above (the white is just the milk fats from the butter). Give it a good stir.

Finished pasta sauce in the slow cooker garnished with parsley

Add salt to the sauce to taste. Start with ½ teaspoon and add more until the flavors pop. I ended up using one teaspoon total. 

Side view of pasta sauce in the slow cooker

Use the slow cooker spaghetti sauce immediately or refrigerate then freeze for long-term storage.

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  1. Not understanding the need for the butter. Just makes it unhealthy.  Use olive oil like a true Italian would and eliminate the sugar.  You can grate carrots which will add nutrients, texture and sweetness. I would never add brown sugar to spaghetti sauce. 

    1. Hi Cynthia! Using butter in sauce is a beloved trick of Marcella Hazan, one of Italy’s most iconic cookbook authors. It helps cut the acidity of the tomatoes. Using sugar is also a technique that originated in southern Italy, as it helps make up for less flavorful end-of-season or out of season tomatoes. Hope this helps make you more comfortable with our recipe! XOXO -Monti

      1. I’d also change sugar to sweet carrots and butter to olive oil. Sugar is never being added to authentic italian pasta sauce

        1. Hi, Almost Italian. Do you! It will be delicious, no matter what. But you’re wrong about the authenticity of sugar and butter in Italian sauces. Marcella Hazan is THE authentic Italian cuisine cookbook author, and she uses both. The sugar, specifically, is a tradition for late-summer tomatoes that need a little added oomph. XOXO -Monti

    1. I haven’t doubled it to know for sure, but I don’t think it will change enough to make a difference. :)

    2. I have doubled this recipe many times and have not found the need to increase the time.  I cook on low for 8 hours and it has always turned out well.

  2. Could I substitute fresh tomatoes for the canned diced ones? If so, how many would you recommend? (I’m looking for a recipe to make sauce out of the garden tomatoes this summer.)

    1. Fresh tomatoes are quite different than canned tomatoes so I’d really need to test them in this recipe to know how it would alter the outcome and whether any other changes would need to be made to compensate.

    2. I used fresh tomatoes from my garden the first time I made this sauce, and it turned out so watery that I decided to finish it in my Dutch oven. It was still delicious! So if you do use fresh, I would either remove as much of the seedy goop as possible or cook on the stovetop for greater evaporation.

  3. Hi from Québec city, Canada!

    If I don’t have a slow cooker , can I do this recipe on the stove or in the oven? If yes, what would be the cooking time? And and would I have to put more liquid in the sauce like water or chicken stock?


    1. Hi Joannie, you can definitely make pasta sauce on the stove top, but unfortunately, I’d need to test this particular recipe before offering specific advice for cook time or if any extra liquid would be needed. :)

    2. I make a similar recipe to this on the stove and just let the sauce simmer for 5-15 minutes or until it gets the right thickness (which is subjective). Stir it pretty often because tomatoes have a tendency to build air bubbles that pop and make a mess.

    3. I just made this tonight on my stove and simmered it for about 2 hours, stirring every 20 mins or so. It’s delicious!

  4. This is my go to sauce now! I have always made a sauce to put on the stove and simmer for hours, with more ingredients as well. But this has more flavor and is so much simpler! Love that I can leave it in the crock pot and not have to babysit it.

  5. First time making this incredible sauce and believe me won’t be the last! WOW! It had so much depth and the caramelization of veggies made it rich. The only thing I wish is I had come across the recipe much earlier in life… I don’t know if I will buy store bought again. I have been telling family and friends of this find. Thank you! The only change I did was included more veggies two carrots shredded and finely minced celery.. always good to throw in hidden veggies!

    1. Yes, we always keep copies of recipes that are removed or changed. I’ll email it to the address you used to register this comment. The only difference is no bay leaf and I added butter.

  6. I have a kit of fresh herbs I’ve been growing can I substitute the dried for fresh?

  7. Can’t wait to see how this turns out. I volunteer for Lasagna Love and am always looking for easy recipes for lasagna prep.

  8. I made the older version some time ago (in a crock pot), and it had a very unpleasant metallic taste to it. What’s the difference between this version and the older one?

    1. The only difference is that I added butter and skipped the bay leaf. I’m not sure where that metallic flavor might have been coming from!

      1. I have noticed that when I put raw onion into any slow cooker recipe, I get a taste like that. I always saute the onion a bit before adding it.

        1. Interesting! Thank you for sharing that! Hopefully that will work better for Janet. :)

          1. The metallic taste could come from the tinned tomatoes. The sugar should offset that but it’ll obviously depend on the variety and manufacturer. Perhaps try using an upmarket brand like Mutti and see if that helps?

    2. To counteract a metallic taste (and to mellow the acid in the tomatoes), add a touch of baking soda. Also, I advise adding the basil near the end of the cooking time rather than in with all the other ingredients at the beginning. Basil is fragile, and adding it too soon leaches out all the flavor. 

  9. Thank you! Can you make a recipe for a slow cooker version of your freezer friendly pizza sauce?

    1. I’m not sure that one needs to be slow-cooked, but I bet you could just use the same recipe and do it in the slow cooker instead of on the stovetop. :)

  10. I have made and enjoyed your original version of this sauce many times. I notice that the big difference in this update is the addition of butter. What does that do to the flavor/texture of the sauce?

    1. I started doing butter with my stove top pasta sauces and now I’m obsessed. It just adds depth and richness to the sauce, and really balances the acidity of the tomatoes nicely. :)