Why it works: Milk and butter are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 81,283 recipes. Both carry (z)-4-heptenal, which smells biscuit, cream. The science ↓
Tomato Soup
Ingredients
Directions
Make the tomato base
Boil the chopped tomatoes in the boiling water until cooked.
Add the baking soda to the tomatoes.
Make the white sauce
In a saucepan, melt the butter over medium heat until bubbling.
Sprinkle in the flour and stir until cooked.
Gradually add the boiling milk to the flour mixture, stirring constantly.
Season with salt and pepper.
Combine and serve
Add the tomato mixture and heat through without boiling.
Serve immediately.
Transcribed from a scanned cookbook and modernised for today's kitchens. Where the book gave no heat or time, or said "a moderate oven", the temperatures and times here may be modern equivalents rather than the book's own figures.
Photo for illustrative purposes only · Contact us to use it
Explore the science
The flavor team
The pairs that carry this dish. Each one is judged two ways: how much their aromas overlap, and how often cooks already put them together.
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Milk + buttertop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
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Tomato + peppertop 7% of all pairsSmell alikemoderateCooked together17,923 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Milk + flourtop 14% of all pairsSmell alikelowCooked together78,219 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Tomato + milktop 15% of all pairsSmell alikemoderateCooked together2,226 recipes
Shared aroma: 1-octen-3-one (mushroom, metallic).
Butter and flour barely smell alike, yet cooks put them together in 124,287 recipes: they work on texture and structure more than aroma.
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Tomatoes
- Provide the main body, acidity and flavour of the soup.
- Baking soda
- Neutralises some of the tomatoes' acid, reducing curdling when milk is added.
- Milk
- Adds creaminess and mild sweetness to the soup.
- Butter
- Adds fat and richness and forms the base of the sauce.
- Flour
- Thickens the butter and milk into a smooth sauce.
The step that matters
Add the tomato mixture without boiling. Once the tomatoes are combined with the milk, high heat can cause the milk proteins to curdle or separate. Heating gently keeps the soup smooth.
Swap the tomato
How well each one fits the dish's main ingredients (milk, butter, flour, pepper):
- Potatofits better
- Capsicumfits better
- Chivefits better
- Tomatothe original
Fit is the average pairing score against milk, butter, flour, pepper. Candidates are from the same food group and used in at least 100 recipes.
“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.
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