Description
A roux of flour cooked in butter thickens the soup through starch gelatinisation, where starch granules absorb water and swell at temperatures between 60 and 80 degrees Celsius. Cream is then stirred in to form a stable emulsion of fat droplets dispersed in the watery tomato base.
Cultural Background
Bisque began as a French soup of crustaceans in the seventeenth century. The name may come from the Bay of Biscay, where fishermen prepared it. American cooks adapted the twice-strained creamy method to tomatoes in the late nineteenth century. One early printed recipe appeared in 1899 in a Buffalo church cookbook that used stewed tomatoes and milk thickened with flour and butter. Starch from the flour forms long chains that tangle in hot liquid and trap water to create thickness. Tomato acids can curdle milk proteins if cream is added too fast or too cool. Gentle heating lets fat globules from the cream break into tiny droplets that stay suspended. Straining after blending removes any remaining skins or seeds for silkiness. The craft step that decides success is tempering the cream by first mixing a ladle of hot soup into it. This equalises temperatures and prevents the proteins from clumping. A true fact is that the word bisque once described soups served only to French nobility before it spread to vegetable versions.
Recipe Info
PREP TIME: 20 minutes
COOK TIME: 40 minutes
TOTAL TIME: 60 minutes
SERVINGS: 4
DIFFICULTY: Medium
Ingredients
- 2 tablespoons unsalted butter
- 1 medium onion, diced
- 1 medium carrot, diced
- 1 celery stalk, diced
- 2 tablespoons all-purpose flour
- 1 28-ounce can crushed tomatoes
- 3 cups low-sodium chicken or vegetable broth
- 1 teaspoon sugar
- 1/2 teaspoon dried thyme
- 1/2 cup heavy cream
- Salt and black pepper to taste
Instructions
- Adult: Melt the butter in a large pot over medium heat.
- Add the onion, carrot and celery and cook, stirring, until the vegetables soften, about 5 minutes.
- Sprinkle in the flour and stir for 2 minutes until the mixture smells slightly nutty.
- Pour in the tomatoes, broth, sugar and thyme.
- Adult: Bring to a boil, then reduce to a simmer and cook 20 minutes.
- Adult: Use an immersion blender or transfer to a blender to puree until smooth.
- Adult: Return the soup to the pot if needed and heat gently.
- Place the cream in a bowl and slowly whisk in one ladle of hot soup.
- Stir the warmed cream mixture back into the pot.
- Season with salt and pepper and serve.
Tips
- The soup can separate if cream is added directly to boiling liquid; watch for small curds forming on the surface.
- Use whole milk instead of cream if needed, though the texture will be lighter.
- Roast fresh tomatoes first next time to deepen flavour through browning reactions.
Nutrition
Calories: 220
Protein: 4g
Carbs: 18g
Fat: 15g