Why it works: Parsley and pepper match in chemistry and in kitchens. They rank in the top 2% of all ingredient pairs, and 34,122 recipes mention both. Both carry 4'-methylacetophenone, which smells bitter almond. The science ↓
Tomato Soup
Ingredients
Directions
Make the soup
In a pot, combine stock, canned tomatoes, chopped onion, parsley, butter, salt, and pepper.
Boil for 30 minutes.
Strain the mixture through a sieve.
Thicken and serve
Dissolve flour or cornstarch in cold water and stir into the soup.
Boil for an additional 5 minutes.
Serve with croutons.
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.
-
Parsley + peppertop 2% of all pairsAroma overlapstrongMentioned together34,122 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
Tomato + peppertop 7% of all pairsAroma overlapmoderateMentioned together17,923 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Tomato + oniontop 8% of all pairsAroma overlapmoderateMentioned together20,633 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Tomato + parsleytop 8% of all pairsAroma overlapmoderateMentioned together5,398 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
Onion + parsleytop 9% of all pairsAroma overlapmoderateMentioned together25,843 recipes
Shared aroma: 2,4-decadienal (seaweed).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Canned tomatoes
- Provide the main body and tomato flavour of the soup.
- Flour or cornstarch
- Thickens the soup as it heats, giving it a smoother body.
- Butter
- Adds fat and richness to the soup's flavour and mouthfeel.
- Onion
- Adds savoury sweetness and depth as it simmers in the broth.
The step that matters
Stirring in the flour or cornstarch. Starch must be dissolved in cold water first so it doesn't clump. Once it hits hot liquid, the starch swells and thickens the soup, so it needs to be boiling briefly to fully thicken and lose its raw taste.
Flavor stand-ins for the onion
How well each one fits the dish's main ingredients (tomato, parsley, butter, pepper, flour):
- Okrabetter flavor fit
- Carrotbetter flavor fit
- Capsicumbetter flavor fit
- Onionthe original
Fit is the average pairing score against tomato, parsley, butter, pepper, 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.
More tomato soup recipes
You might also like
Tomato Bisque61 recipes
Tomato Fritters23 recipes
Tomato Puree23 recipes
Macaroni with Tomato Sauce16 recipesThe Sunday pairing: one pairing, the chemistry behind it, and how to cook it. No spam, unsubscribe anytime.
Prefer an account? Create a free account for sign-in; Pro adds the full results and chemistry.