Why It Works
- Unlike oil, butter browns as it cooks to lend the soup a bit of nutty depth.
- Carrot purée adds an earthy sweetness to balance the acidic tomatoes, and creates a creamy consistency without the need for much cream.
- A small pinch of baking soda will tame any unwanted acidity in the soup.
With only a splash of cream per serving, the secret to the creamy consistency of this tomato basil soup is carrot purée. Its subtle sweetness mellows the acidity of canned tomatoes, for a hearty soup that feels like a meal on its own. Finished with a handful of fresh basil, this soup is the perfect accompaniment to any salad or grilled cheese.
- 4 ounces unsalted butter (1 stick; 114g)
- 4 large carrots (1 pound; 455g), diced (see note)
- 2 medium yellow onions (1 pound; 455g), diced (see note)
- 3 large (28-ounce/795g) cans whole tomatoes, crushed roughly by hand
- 4 cups (950ml) homemade or store-bought low-sodium chicken stock
- 1/4 teaspoon baking soda, plus more as needed (optional)
- 8 ounces heavy cream (1 cup; 225g)
- Up to 1 1/4 teaspoons (5g) Diamond Crystal kosher salt
- 1/2 teaspoon (1g) freshly ground black pepper, or more to taste
- 1/8 teaspoon ground cayenne, or more to taste
- 1/2 ounce fresh basil leaves (1 loosely packed cup; 15g), cut into chiffonade
In a 6-quart stainless steel pot, melt butter over medium heat until foaming, then add carrots and onions. Cook, stirring occasionally, until butter starts to brown on the bottom, about 15 minutes. Add tomatoes, followed by chicken stock. Continue cooking, stirring occasionally, until quite thick, about 1 1/2 hours; adjust heat as needed to maintain a gentle simmer.
Taste broth; if its flavor is too sharp or acidic, add 1/4 teaspoon baking soda and stir well (it will foam at first). Taste and repeat if needed. Purée soup with an immersion blender until smooth, or cool until no longer steaming before puréeing in a countertop blender. Stir in cream, then season with salt, pepper, and cayenne to taste. Rewarm to serve. Stir in basil just before serving. In a sealed nonreactive container, tomato soup will keep up to 1 week in the refrigerator or 6 months in the freezer.
The size of a "medium" onion or a "large" carrot is inherently subjective, so the specifics of the vegetables listed above are meant as a guide rather than some draconian rule. The recipe itself works quite well give or take a few ounces either way.
Make-Ahead and Storage
In a sealed nonreactive container, tomato soup will keep up to 1 week in the refrigerator, or 6 months in the freezer.