Why it works: Pepper and lemon match in chemistry and in kitchens. They rank in the top 3% of all ingredient pairs, and cooks put them together in 27,047 recipes. Both carry trans-2-nonenal, which smells cardboard, fatty. The science ↓
Another Calf S- Head Soup
Ingredients
Directions
Make the base
Boil 6 onions in veal or beef stock.
Brown 2 ounces of butter and thicken it with flour.
Gradually add the stock to the butter mixture until it boils.
Simmer and finish
Add the calf's head pieces and fried forcemeat balls.
Season with salt and pepper, and add the peel of ½ lemon.
Boil for 20 minutes.
Stir in 2 tablespoons of catsup, 3 tablespoons of essence of anchovies, and enough lemon pickle for a pleasant acidity.
Mix 1 tablespoon of flour with 1 teacup of cold water until smooth, then stir it into the soup.
Let the soup boil for a few more minutes.
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.
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Pepper + lemontop 3% of all pairsSmell alikestrongCooked together27,047 recipes
Shared aroma: trans-2-nonenal (cardboard, fatty).
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Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Onion + buttertop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
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Butter + lemontop 16% of all pairsSmell alikemoderateCooked together41,227 recipes
Shared aroma: 3-hexenal (apple, fruity).
Butter and flour barely smell alike, yet cooks put them together in 124,287 recipes: they work on texture and structure more than aroma.
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Butter
- Browned with flour to form a roux that thickens the soup and adds a nutty aroma.
- Flour
- Thickens the butter and stock, giving the soup body through starch gelatinisation.
- Calf's head
- Provides the main meat and gelatin, giving the soup richness and a silky body.
- Essence of anchovies
- Adds savoury depth and umami to the soup.
- Lemon pickle
- Adds acidity that brightens the rich, savoury broth.
The step that matters
Stirring in the flour and cold water slurry. Flour added directly to hot liquid clumps, so it must be whisked smooth with cold water first. Then the soup must boil for a few minutes so the starch fully thickens and loses its raw flour taste.
Swap the onion
How well each one fits the dish's main ingredients (veal, butter, flour, pepper, lemon):
- Shallotfits better
- Leekfits better
- Spinachfits better
- Onionthe original
Fit is the average pairing score against veal, butter, flour, pepper, lemon. 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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