Why it works: Onion and tomato are a kitchen classic. They rank in the top 8% of all ingredient pairs, and 20,633 recipes mention both. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Tomato Soup
Ingredients
Directions
Make the tomato base
Cut the onion and fry it in oiled butter until brown.
Remove the onion and add the tomatoes.
Stew the tomatoes gently until tender.
Pulp the tomatoes through a sieve.
Finish the soup
Add the pulped tomatoes to the prepared stock.
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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Onion + tomatotop 8% of all pairsAroma overlapmoderateMentioned together20,633 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Onion + buttertop 15% of all pairsAroma overlapmoderateMentioned together42,912 recipes
Shared aroma: decanal (soap, orange peel).
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Butter + tomatotop 22% of all pairsAroma overlapmoderateMentioned together6,918 recipes
Shared aroma: 3-hexenal (apple, fruity).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Onion
- Frying until brown adds savoury, sweet depth to the soup's flavour.
- Tomatoes
- Form the main body and flavour of the soup once stewed and pulped.
- Stock
- Provides the liquid base and savoury backbone of the soup.
The step that matters
Stew the tomatoes gently until tender. Gentle heat softens the tomatoes without scorching them, so they pulp smoothly and the flavour stays fresh rather than burnt or bitter.
Flavor stand-ins for the onion
How well each one fits the dish's main ingredients (butter, tomato):
- Capsicumbetter flavor fit
- Potatobetter flavor fit
- Okraabout as good a flavor fit
- Onionthe original
Fit is the average pairing score against butter, tomato. 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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