Slow Cooker Creamy Tomato Basil Soup

I’ve had this recipe on my website since 2014… in fact, it’s one of the very first recipes I shared!

We still make this creamy tomato soup often, and over the years, I’ve tweaked it slightly, changed things up to prevent any curdling, and developed more ways to cook this soup.

If you’re a fan of canned creamy tomato soup, let me tell you, you won’t want to buy those cans ever again after you try this homemade version.

The flavors are absolutely incredible! The acidic tomatoes, sweet basil, velvety cream, and salty Parmesan all come together in a bowl of pure deliciousness.

This soup is made in a slow cooker, but don’t worry, I’ve shared how to make it in the Instant Pot, as well as on the stovetop. No matter which version you make, you’ll love how easy it is!

How to make creamy tomato basil soup?

This is just an overview; the full ingredients and directions are in the recipe card toward the bottom of this post.

1. Add tomato soup base to slow cooker. That’s the diced tomatoes, tomato sauce, tomato paste, onion, garlic, basil, salt, pepper, and chicken broth.
2. Slow cook. Cover and cook on low for 6-8 hours.
3. Make roux. This thickens the soup a bit, and adds undeniable creaminess! Melt butter, then add flour and whisk. Whisk in the milk and cream and cook a few minutes, until thickened slightly.
4. Add cheese. To the roux, add Parmesan cheese and stir until smooth.
5. Pour roux into slow cooker. Give it a good stir, then leave it uncovered and cook about 20 more minutes, stirring occasionally.
6. Serve. Serve hot, sprinkled with Parmesan cheese, and fresh basil.

Variations of this recipe

• Non-creamy – creamy tomato soup not your thing? You can simply leave off the roux and dairy, and have a rich, traditional tomato basil soup.
• Vegetarian – we like to use chicken broth as the liquid in the soup since it adds great flavor, but if you’re a vegetarian, swap that for vegetable broth.
• Dairy – we like the combination of the evaporated milk and heavy cream, but feel free to play around with different types of dairy that you have on hand (milk, half and half, all evaporated milk, all cream, etc). I haven’t specifically tested with non-dairy milks, but I *think* they should work well.
• Fresh tomatoes – in the summer, this soup can be made using fresh tomatoes if you have some on hand. You’ll want about 3 lbs of tomatoes (peeled or unpeeled, it’s up to you), and you can use less chicken broth (since the tomatoes will give off quite a bit of liquid as they cook). Obviously you can omit the canned tomatoes and tomato sauce, but I’d probably keep the tomato paste in, since it adds a deeper flavor.
• Other cooking methods – as written, this is for a slow cooker soup, but you can easily make this recipe in other ways. Check out the “chef tips” section below the recipe for all the details (stovetop and Instant Pot versions).

Making tomato soup ahead of time

Soups are amazing to make ahead of time, since most of the time, they actually taste better the next day! All the flavors have had time to really meld together.

This tomato basil soup should last for several days in the refrigerator, so feel free to make it completely ahead of time if you’d like.

Storage

Leftover soup should be refrigerated in an airtight container and enjoyed within 4-5 days.

Reheat however you prefer (microwave, stovetop or Instant Pot).

Freezing

This tomato soup recipe can be frozen! Due to the dairy in it, I do recommend freezing it before adding the roux and cheese.

Let the soup cool completely, then transfer to a freezer-safe container, label with the date, and freeze for up to 3-6 months.

Thaw in the refrigerator, then proceed with the roux instructions and heat.

Original recipe from 2014 was inspired by Le Creme de la Crumb

Original Recipe from 2014

• 2 (15 oz each) cans diced tomatoes
• 1 (10 oz) can tomato sauce
• 1/4 cup fresh basil, finely chopped
• 2 cloves garlic, minced
• 1 Tbsp salt
• 1 tsp pepper
• 1 onion, diced
• 1 cup heavy cream
• 4 cups chicken broth (or vegetable broth)
• 2 cups shredded Parmesan cheese
• 3 Tbsp butter
• 1/4 cup flour
• 1 cup heavy cream

1. Add tomatoes, tomato sauce, garlic, onion, basil, salt, pepper, heavy cream and vegetable or chicken broth to your crockpot. Cover and cook on low for 6-8 hours (although it can be done on high for 2 hours as well). Stir occasionally and scrape down the sides (if you can).
2. 40 minutes before serving, transfer soup to a blender or food processor and puree until smooth. Return to crockpot.
3. Make your roux by melting your butter in a saucepan over medium heat. Once butter is melted, add the flour and whisk until it’s incorporated. Slowly whisk in the heavy cream until the cream is smooth and thickened.
4. Add Parmesan cheese and roux to the crockpot and stir to combine.
5. Cook for another 20-30 minutes. Cheese should be completely melted into the soup. Stir thoroughly before serving. Garnish with additional Parmesan cheese and basil if desired.