Why it works: Endive and lettuce match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 284 recipes. Both carry trans-2-hexenal, which smells green, leafy. The science ↓
White Soup Without Meat
Ingredients
Directions
Make the soup
Put 2 quarts of water in a clean saucepan.
Add the bread crumb, sweet herbs, pepper, cloves, chopped onion, and salt.
Boil for 30 minutes.
Add the cut white parts of celery, endive, and lettuce.
Boil until smooth.
Strain the soup.
Finish and serve
Return the strained soup to the fire.
When it begins to boil, add the butter rolled in flour.
Boil for a few more minutes.
Serve.
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 their aromas overlap, and how often cooks already put them together.
-
Endive + lettucetop 1% of all pairsSmell alikestrongCooked together284 recipes
Shared aroma: trans-2-hexenal (green, leafy).
-
Celery + lettucetop 4% of all pairsSmell alikestrongCooked together2,033 recipes
Shared aroma: nonanal (fat, citrus).
-
Pepper + clovetop 5% of all pairsSmell alikestrongCooked together17,451 recipes
Shared aroma: ethyl octanoate (fruity, wine).
-
Pepper + celerytop 5% of all pairsSmell alikestrongCooked together16,012 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
Celery + endivetop 5% of all pairsSmell alikestrongCooked together160 recipes
Shared aroma: nonanal (fat, citrus).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Baker's loaf crumb
- Thickens the broth and gives the soup body as it breaks down during boiling.
- Butter rolled in flour
- Adds richness and fat, and the flour helps thicken the soup when it is stirred in.
- Celery, endive, and lettuce
- Contribute vegetable flavor and, once boiled, help make the soup smooth.
- Onion
- Adds savory aromatic flavor to the broth.
The step that matters
Adding the butter rolled in flour. Flour clumps if dropped in loose, so it must be rolled into the butter first and added to a simmering liquid. Stirring it in well keeps the soup smooth and evenly thickened rather than lumpy.
Swap the onion
How well each one fits the dish's main ingredients (pepper, clove, celery, endive, lettuce, butter, flour):
- Turnipfits better
- Leekfits better
- Beetrootfits better
- Onionthe original
Fit is the average pairing score against pepper, clove, celery, endive, lettuce, butter, flour. Candidates are from the same food group and used in at least 100 recipes.
“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 white soup recipes
You might also like
The free Flavor Lab newsletter: one surprising pairing a week and the molecular reason it works, in 60 seconds. No spam, unsubscribe anytime.
Prefer an account? Create a free account to save pairings and unlock the full chemistry.

Cream of Celery Soup113 recipes
Celery Stew25 recipes
Celery Croquettes16 recipes
Celery Cream Soup15 recipes