Why it works: Butter and milk 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
In a pot, combine the tomatoes, chopped onion, salt, and water. Boil for 30 minutes and then strain.
Make the butter mixture
In a separate bowl, cream the butter and flour together.
Add the sugar, cayenne pepper, and milk to the butter mixture.
Combine and serve
Combine this mixture with the strained tomato broth and heat through before serving.
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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Butter + milktop 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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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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.
- Butter
- Adds richness and a smooth, rounded mouthfeel to the soup.
- Flour
- Mixed with butter to thicken the soup and give it body.
- Milk
- Adds creaminess and softens the sharp tomato acidity.
- Sugar
- Balances the acidity of the tomatoes with sweetness.
The step that matters
Combining the butter mixture with the tomato broth. Adding the flour and butter mixture to hot liquid without first blending it smooth can cause lumps. Combine it gradually and heat gently so the flour thickens the soup evenly without scorching or curdling the milk.
Swap the onion
How well each one fits the dish's main ingredients (tomato, butter, flour, sugar, pepper, milk):
- Capsicumfits better
- Potatofits better
- Sweet potatofits better
- Onionthe original
Fit is the average pairing score against tomato, butter, flour, sugar, pepper, milk. 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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