Why it works: Turnip and celery are a kitchen classic. They rank in the top 2% of all ingredient pairs, and cooks put them together in 4,418 recipes. Both carry coumarin, which smells sweet, hay. The science ↓
Onion Soup
Ingredients
Directions
Prepare the vegetables
Slice the onions, turnips, and celery.
Fry them in butter until browned but not burnt.
Make the soup
Add the vegetables to boiling water with the herring or anchovies, mace, allspice, pepper, and salt.
Let the mixture stew until tender enough to pulp.
Boil the roll crumbs in milk, then pass them through a colander with the vegetables.
Return the mixture to the heat and stew until hot.
If the soup is not thick enough, beat in the raw egg yolks just before serving.
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.
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.
-
Turnip + celerytop 2% of all pairsSmell alikemoderateCooked together4,418 recipes
Shared aroma: coumarin (sweet, hay).
-
Celery + peppertop 5% of all pairsSmell alikestrongCooked together16,012 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
Allspice + peppertop 5% of all pairsSmell alikestrongCooked together6,395 recipes
Shared aroma: estragole (anise, licorice).
-
Onion + turniptop 5% of all pairsSmell alikestrongCooked together7,585 recipes
Shared aroma: coumarin (sweet, hay).
-
Turnip + allspicetop 6% of all pairsSmell alikestrongCooked together445 recipes
Shared aroma: coumarin (sweet, hay).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Onions
- Form the bulk of the soup and build its sweet, savory flavor when browned.
- Butter
- Fries the vegetables, adding richness and helping them brown.
- French roll crumbs
- Soaked in milk and pulped in, they thicken the soup and give it body.
- Egg yolks
- Enrich and thicken the soup when beaten in just before serving.
The step that matters
Frying the vegetables in butter. Browning caramelizes the sugars in the onions and turnips, building color and depth; if they burn, the soup turns bitter.
Swap the mace
How well each one fits the dish's main ingredients (onion, turnip, celery, butter, anchovy, allspice, pepper):
- Parsleyfits better
- Thymefits better
- Capersfits better
- Macethe original
Fit is the average pairing score against onion, turnip, celery, butter, anchovy, allspice, pepper. 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.
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