Slow Cooker Tomato Soup: A Comforting Classic Recipe

I perfected my Slow Cooker Creamy Tomato Soup with a single pantry hack and an unexpected ingredient that turns plain tomatoes into something surprisingly impressive.

I’ve always loved a bowl of tomato soup. Is there anything more comforting than a warm, creamy tomato soup?

It’s a classic that always hits the spot. And the best part?

You. I usually toss a yellow onion into the slow cooker, let everything slow down, then finish with a splash of heavy cream for that silky finish.

This became my go to Overnight Crockpot Tomato Soup when I needed something low fuss, and sometimes I chase nostalgia by trying a Copycat Campbell’s Tomato Soup version, which never comes out the same but somehow feels just right.

Ingredients

• Tomatoes give vitamin C, fiber and bright acidity it makes the soup tangy and fresh.
• Tomato paste is concentrated, deepens color and richness, adds umami and a bit of sweetness.
• Onion gets sweet when cooked, gives savory depth plus fiber and antioxidants.
• Garlic punches flavor, it’s pungent and has immune boosting compounds, tiny but strong.
• Carrot adds gentle sweetness, beta carotene for vitamin A and a bit of body.
• Olive oil adds healthy fats and silkiness, butter makes it richer if you like.
• Broth gives savory backbone, thins or deepens soup, brings minerals and umami.
• Cream smooths acidity, adds creamy mouthfeel, it’s indulgent and higher in calories.
• Parmesan rind drops salty, nutty umami into the pot, subtle but powerful.

Ingredient Quantities

• 2 tablespoons olive oil
• 2 tablespoons unsalted butter (optional)
• 1 medium yellow onion, diced
• 3 cloves garlic, minced
• 1 large carrot, peeled and grated
• 2 (28-ounce) cans crushed tomatoes
• 2 tablespoons tomato paste
• 3 cups low-sodium vegetable or chicken broth
• 1 bay leaf
• 1 teaspoon dried basil
• 1/2 teaspoon dried oregano
• 1 teaspoon granulated sugar (optional)
• 1 to 1 1/2 teaspoons kosher salt
• 1/4 teaspoon black pepper
• 1/2 cup heavy cream or half-and-half
• 1 Parmesan rind (optional)
• Pinch red pepper flakes (optional)
• Fresh basil leaves for garnish (a handful, optional)

How to Make this

1. heat 2 tablespoons olive oil and 2 tablespoons unsalted butter (optional) in a large skillet over medium heat until butter foams, add 1 diced medium yellow onion and cook 5 to 7 minutes until soft and translucent.

2. add 3 minced garlic cloves and the grated large carrot, cook 1 to 2 minutes more until fragrant, then stir in 2 tablespoons tomato paste and cook another minute to deepen the flavor.

3. transfer the sautéed veggies and paste to the slow cooker, pour in 2 (28-ounce) cans crushed tomatoes and 3 cups low-sodium vegetable or chicken broth, stir to combine.

4. add 1 bay leaf, 1 teaspoon dried basil, 1/2 teaspoon dried oregano, 1 teaspoon granulated sugar (optional), 1 to 1 1/2 teaspoons kosher salt, 1/4 teaspoon black pepper, a pinch of red pepper flakes (optional) and the Parmesan rind (optional) into the slow cooker, give it a good stir.

5. cook on low for 4 to 6 hours or on high for 2 to 3 hours; you want the flavors married and the carrot fully tender.

6. remove the bay leaf and Parmesan rind, then use an immersion blender to puree until smooth. if you dont have one, ladle soup in batches into a blender but cool slightly and vent the lid, fill it only half full.

7. for an ultra silky soup, strain through a fine mesh sieve back into the pot, pressing with a spoon, but this step is optional if you like a bit more texture.

8. return soup to low heat and stir in 1/2 cup heavy cream or half-and-half, warm gently 5 to 10 minutes more, taste and adjust salt, pepper or sugar if needed, add more broth if it’s too thick.

9. ladle into bowls, garnish with fresh basil leaves and grated Parmesan if you like, serve with grilled cheese or crusty bread. enjoy.

Equipment Needed

1. Large skillet (12-inch works) for sautéing the onion and carrot
2. Chef’s knife and cutting board, for chopping and prepping
3. Box grater or microplane, to grate the carrot and Parmesan
4. Wooden spoon or heatproof spatula, for stirring the veggies and tomato paste
5. Slow cooker (4 to 6 quart) to simmer the soup low and slow
6. Measuring cups and spoons, for broth, oil, tomato paste and seasonings
7. Can opener for the crushed tomatoes
8. Immersion blender, or a regular blender to puree the soup
9. Fine mesh sieve (optional) to make the soup extra silky
10. Ladle, serving bowls and a small grater for finishing Parmesan

FAQ

Slow Cooker Tomato Soup: A Comforting Classic Recipe Substitutions and Variations

• Olive oil: swap with avocado or canola oil, 1:1. They’re neutral and handle heat better than extra-virgin so it won’t change the soup much.
• Unsalted butter (optional): use ghee or coconut oil in the same amount. Ghee keeps the buttery flavor without milk solids, coconut oil will add a slight taste so only use if you like it.
• Heavy cream or half-and-half: use full-fat coconut milk 1:1 for a dairy-free, creamy result, or thin whole milk thickened with 1 tsp cornstarch per 1/2 cup for a lighter finish.
• Parmesan rind (optional): grate in 1/4 cup Parmesan near the end instead, or for a vegan option stir in 1 to 2 tbsp nutritional yeast to boost savory umami.

Pro Tips

1) Caramelize more than you think. Let the onions and tomato paste get really golden, not just soft. That deep, slightly sweet flavor makes the whole soup taste richer. Just watch the heat so the paste doesn’t burn.

2) Use the carrot smartly. Grate it super fine or puree a portion before adding if you want silkier texture. If the soup ends up too sweet, brighten it with a splash of vinegar or extra salt instead of more sugar.

3) Treat the Parmesan rind like secret seasoning. Simmer it in while the soup cooks and pull it out before blending. It adds umami without making the soup taste cheesy, and you can stir in a little grated Parmesan at the end if you want more punch.

4) Blend and finish gently. Cool a bit before using a countertop blender and vent the lid, or use an immersion blender to avoid hot splatters. For an ultra smooth feel, push the blended soup through a fine sieve and warm it back up slowly, then swirl in the cream at the end so it stays bright and not curdled.