Why it works: Pepper and tomato are a kitchen classic. They rank in the top 7% of all ingredient pairs, and 17,923 recipes mention both. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Quick Tomato Soup
Ingredients
Directions
In a large pot, combine water, tomatoes, salt, pepper, and onion.
Heat the mixture to boiling.
In a separate bowl, mix butter and flour to form a paste.
Add the paste to the boiling soup and cook for a few minutes.
Strain the soup and serve.
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.
Explore the science
The flavor team
The pairs that carry this dish. Each one is judged two ways: how much aroma chemistry they share, and how many recipes mention both.
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Pepper + tomatotop 7% of all pairsAroma overlapmoderateMentioned together17,923 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Onion + tomatotop 8% of all pairsAroma overlapmoderateMentioned together20,633 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Pepper + oniontop 11% of all pairsAroma overlapmoderateMentioned together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Butter + flourtop 12% of all pairsAroma overlaplowMentioned together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Onion + buttertop 15% of all pairsAroma overlapmoderateMentioned together42,912 recipes
Shared aroma: decanal (soap, orange peel).
Butter and flour share little aroma chemistry, yet 124,287 recipes mention both: they likely 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 and flavor of the soup.
- Butter
- Adds richness and fat to the soup.
- Flour
- Mixed with butter to form a paste that thickens the soup.
The step that matters
Adding the butter and flour paste. Flour needs to be blended smoothly with fat first and then stirred into hot liquid; if added lumpy or without enough stirring, it clumps instead of thickening evenly.
Flavor stand-ins for the onion
How well each one fits the dish's main ingredients (pepper, tomato, butter, flour):
- Capsicumbetter flavor fit
- Okrabetter flavor fit
- Eggplantbetter flavor fit
- Onionthe original
Fit is the average pairing score against pepper, tomato, butter, flour. Candidates are from the same food group and used in at least 100 recipes. This compares flavor only: it does not check the job the ingredient does in the dish (bulk, moisture, acidity, structure).
“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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