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
Combine the tomatoes, water, and chopped onion in a pot.
Season with salt and pepper, and cook together for 2 hours.
Mix the flour with cold milk until smooth. Add the flour mixture and butter to the pot.
Stir well and serve hot.
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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Tomato + oniontop 8% of all pairsSmell alikemoderateCooked together20,633 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Flour + buttertop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
Flour and butter 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, flavor, and liquid base of the soup.
- Flour
- Thickens the soup and gives it a smoother, fuller body.
- Butter
- Adds richness and a silkier mouthfeel to the finished soup.
- Milk
- Mixed with flour to a smooth paste, then adds creaminess when stirred in.
The step that matters
Mix the flour with cold milk until smooth. Flour added directly to hot liquid clumps; whisking it into cold milk first disperses the starch so it thickens the soup evenly.
Swap the onion
How well each one fits the dish's main ingredients (tomato, pepper, flour, milk, egg, butter):
- Capsicumfits better
- Potatofits better
- Asparagusfits better
- Onionthe original
Fit is the average pairing score against tomato, pepper, flour, milk, egg, butter. 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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