Why it works: Tomato and pepper 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 ↓
Tomato Soup
Ingredients
Directions
Simmer the soup
Boil the tomatoes in the stock with the onion and sugar for about 1 hour.
Thicken the soup with the pea flour and season with pepper and salt.
Let it simmer gently for 20 minutes after thickening.
Finish and serve
Strain the soup 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 aroma chemistry they share, and how many recipes mention both.
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Tomato + peppertop 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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Onion + peppertop 11% of all pairsAroma overlapmoderateMentioned together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Sugar + flourtop 15% of all pairsAroma overlapmoderateMentioned together92,116 recipes
Shared aroma: phenylacetaldehyde (hawthorne, honey).
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Onion + flourtop 17% of all pairsAroma overlapmoderateMentioned together32,460 recipes
Shared aroma: isobutyraldehyde (malty, green).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Tomatoes
- Provide the main flavour and the bright acidity of the soup.
- Stock
- Forms the liquid base and adds savoury depth as it reduces.
- Onion
- Adds aromatic, savoury sweetness as it softens during boiling.
- Sugar
- Balances the tomatoes' acidity with a touch of sweetness.
- Pea flour
- Thickens the soup by absorbing liquid and giving it body.
The step that matters
Thickening with pea flour. Flour must be fully dispersed into the hot soup and then simmered so it thickens evenly without lumps and loses its raw, floury taste. Stirring while adding it and simmering afterward helps achieve this.
Flavor stand-ins for the onion
How well each one fits the dish's main ingredients (tomato, sugar, flour, pepper):
- Capsicumbetter flavor fit
- Okrabetter flavor fit
- Eggplantbetter flavor fit
- Onionthe original
Fit is the average pairing score against tomato, sugar, flour, pepper. 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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