Slow Cooker Tomato Soup

A creamy and nostalgic childhood favorite, this Slow Cooker Tomato Soup cooks gently all day, filling your home with the most amazing scent that makes everyone eager for dinner time. This creamy tomato soup is made with just a few ingredients but has a well-rounded and robust flavor.

Have you ever tried Marcella Hazan's famous tomato sauce? I first learned of that simple, yet profound butter and onion tomato sauce about a decade ago, and it is now the only way I make tomato sauce. Over the years I've tweaked it to fit my own preferences, adding a bit more spices and herbs, as well as a pinch of sugar. I also started cooking it in the slow cooker all day. My family loves it so much that I started using that basic technique of cooking the tomatoes with a whole onion and butter to make tomato soup too.

This Slow Cooker Tomato Soup is a riff on that famous tomato sauce. It's well-balanced, super flavorful, and incredibly creamy. Plus, it's made simply in the slow cooker with really no hands-on cooking time. It is my kids' favorite soup recipe, and I hope it becomes a favorite in your home too.

So let's get to making it! The text below offers some tips for making it, or you can scroll down to the bottom for the complete recipe.

Ingredients and Substitutions

Here is a brief overview of the ingredients needed for this recipe. The full recipe with quantities is listed below this text in the recipe card. If substitutions are available for this recipe, they'll be listed here. If you don't see a substitution you are looking for, feel free to leave a comment below.

• whole peeled san marzano tomatoes + crushed san marzano tomatoes (see note)
• onion
• butter
• sugar
• kosher salt
• garlic powder
• dried oregano
• chicken or veggie broth (use chicken unless you need this to be a vegetarian soup)
• heavy cream

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Why San Marzano Tomatoes?

This recipe calls for two different types of canned tomatoes, with both of them being San Marzano tomatoes. This is simply because they lend the best flavor for this recipe as far as canned tomatoes are concerned. This recipe is so easy, except for this small instruction of calling for a very specific type of tomato. They are worth the effort to seek out and buy for this recipe.

Can you make this recipe without canned San Marzano? Sure, it just won't be as good.

The one exception to this is if you are using homegrown or farm heirloom tomatoes. And you certainly can use those for this recipe, just be sure to remove the skin and stem from them before using them in this recipe.

Why the Slow Cooker is the Best Kitchen Tool for this Tomato Soup

Not only is using the slow cooker a good choice for making dinner (for all the obvious reasons) but it also is key to the deep flavor of this tomato soup recipe. The low and slow simmer of the tomato sauce with the butter and onion really helps to soften the acidity just enough, while enhancing the tomato flavor. It's a truly smooth and enjoyable tomato soup.

Freezing Tomato Soup

This tomato soup freezes really well. It's best if it's frozen without the addition of heavy cream. So if you are making it with plans to freeze it for later use, omit the cream until after it has been defrosted.

However, I have successfully frozen it with the heavy cream, though sometimes I need to run it through the blender after it defrosts.

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Making the recipe? Be sure to leave a comment with a star review on your experience! Have a question? Leave a comment below and I’ll get back to you as quickly as I can!

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