Why it works: Celery and parsley match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and 6,810 recipes mention both. Both carry 4'-methylacetophenone, which smells bitter almond. The science ↓
Tomato Soup
Ingredients
Directions
Prepare the soup
Melt the butter in a saucepan over medium heat.
Add the chopped bacon and sliced onion, and fry for about 5 minutes without browning.
Stir in the tomatoes, stock, and celery. Bring to a boil, then simmer gently for 30 to 45 minutes.
Pass the mixture through a fine sieve back into the saucepan.
Thicken and serve
Mix the cornflour with a little water to form a smooth paste, then stir it into the tomato mixture.
Bring to a boil and cook for 10 minutes, stirring well.
Season with salt and pepper, pour into a tureen, and sprinkle with parsley.
Serve with small pieces of fried bread on the side.
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.
-
Celery + parsleytop 1% of all pairsAroma overlapstrongMentioned together6,810 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
Parsley + peppertop 2% of all pairsAroma overlapstrongMentioned together34,122 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
Tomato + celerytop 4% of all pairsAroma overlapmoderateMentioned together3,377 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
Celery + peppertop 5% of all pairsAroma overlapstrongMentioned together16,012 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
Onion + celerytop 7% of all pairsAroma overlapmoderateMentioned together18,518 recipes
Shared aroma: guaiacol (smoky, sweet).
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, acidity and flavour of the soup.
- Butter
- Adds fat and richness and carries flavour from the onion and bacon.
- Cornflour
- Thickens the soup into a smooth, silky texture when cooked with liquid.
- Onion
- Builds a sweet, savoury base flavour as it softens in the fat.
The step that matters
Sieving the cooked mixture. Pressing the cooked tomato, onion and celery through a fine sieve removes skins, seeds and fibres, giving a smooth texture before the soup is thickened.
Flavor stand-ins for the onion
How well each one fits the dish's main ingredients (tomato, butter, celery, parsley, pepper):
- Carrotbetter flavor fit
- Capsicumbetter flavor fit
- Potatobetter flavor fit
- Onionthe original
Fit is the average pairing score against tomato, butter, celery, parsley, 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.
More tomato soup recipes
You might also like
The 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.

Cream of Celery Soup113 recipes
Tomato Bisque61 recipes
Celery Stew25 recipes
Tomato Fritters23 recipes