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 ↓
Cream of Tomato Soup
Ingredients
Directions
Make the milk base
Scald the milk with the onion, then remove the onion.
Thicken the milk with flour diluted in cold water until it is thin enough to pour, ensuring there are no lumps.
Cook the mixture in a double boiler for twenty minutes, stirring constantly at first.
Make the tomato base
Cook the tomatoes with sugar for fifteen minutes, then add baking soda and rub through a sieve.
Combine and serve
Combine the tomato mixture with the milk mixture, and strain into a tureen over the butter, salt, and pepper.
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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Pepper + tomatotop 7% of all pairsSmell alikemoderateCooked together17,923 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Onion + tomatotop 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
- Milk
- Forms the creamy body of the soup once thickened and heated.
- Flour
- Thickens the milk so the soup becomes pourable and smooth rather than watery.
- Tomatoes
- Provide the main flavor and acidity of the soup.
- Baking soda
- Neutralizes some of the tomato's acidity, softening its sharpness and keeping the milk from curdling.
- Butter
- Adds richness and a silky mouthfeel to the finished soup.
The step that matters
Adding the tomato mixture to the milk. Acidic tomatoes can curdle hot milk. Baking soda is added to the tomatoes first to reduce acidity, and the milk should be well thickened and the tomatoes combined carefully so the soup stays smooth.
Swap the onion
How well each one fits the dish's main ingredients (milk, sugar, flour, pepper, butter, tomato):
- Capsicumfits better
- Potatofits better
- Sweet potatofits better
- Onionthe original
Fit is the average pairing score against milk, sugar, flour, pepper, butter, tomato. 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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