Why it works: Tomato and onion 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
Prepare
Peel the vegetables and slice the vegetables.
Cut the bacon into small slices.
Make the soup
Fry the bacon in butter until light brown, then remove the bacon.
Fry the vegetables in the same pan.
Add water or nicely seasoned white stock.
Cook until tender.
Pass the mixture through a fine sieve.
Return the mixture to the saucepan and warm it.
Thicken gradually with semolina while stirring for 5 minutes.
Serve
Serve with crumpled bread.
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.
-
Tomato + oniontop 8% of all pairsAroma overlapmoderateMentioned together20,633 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Onion + buttertop 15% of all pairsAroma overlapmoderateMentioned together42,912 recipes
Shared aroma: decanal (soap, orange peel).
-
Onion + semolinatop 17% of all pairsAroma overlapmoderateMentioned together99 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Tomato + semolinatop 18% of all pairsAroma overlapmoderateMentioned together44 recipes
Shared aroma: 1-octen-3-ol (mushroom, earthy).
-
Tomato + buttertop 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
- Tomatoes
- Provide the main body, flavour and acidity of the soup.
- Onion
- Adds sweetness and savoury depth as it softens in the fat.
- Bacon
- Adds savoury, smoky flavour to the fat used for frying the vegetables.
- Semolina
- Thickens the soup as its starch swells with heat and stirring.
- Butter
- Carries the bacon flavour and enriches the soup with fat.
The step that matters
Thicken gradually with semolina while stirring. Semolina added all at once clumps and resists mixing. Adding it slowly while stirring lets the starch disperse and swell evenly, giving a smooth, uniformly thickened soup.
Flavor stand-ins for the onion
How well each one fits the dish's main ingredients (tomato, semolina, butter):
- Potatobetter flavor fit
- Capsicumbetter flavor fit
- Spinachbetter flavor fit
- Onionthe original
Fit is the average pairing score against tomato, semolina, butter. 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.