Why it works: Flour and capers match in chemistry and in kitchens. They rank in the top 6% of all ingredient pairs, and cooks put them together in 1,024 recipes. Both carry isobutyraldehyde, which smells malty, green. The science ↓
Caper Sauce
Ingredients
Directions
In a bowl, mix the butter and flour together.
Pour boiling water over the mixture until it thickens.
Chop the hard boiled egg finely and add it to the mixture.
Stir in the capers.
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.
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Flour + caperstop 6% of all pairsSmell alikestrongCooked together1,024 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Flour + eggtop 15% of all pairsSmell alikelowCooked together106,462 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Butter + caperstop 16% of all pairsSmell alikemoderateCooked together1,637 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Butter + eggtop 17% of all pairsSmell alikemoderateCooked together118,967 recipes
Shared aroma: decanal (soap, orange peel).
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
- Adds richness and smooth body to the sauce, carrying flavor.
- Flour
- Thickens the sauce when combined with butter and hot water.
- Capers
- Add a sharp, acidic, briny flavor that cuts the richness of the butter.
- Hard boiled egg
- Adds body and a soft, creamy texture to the sauce.
The step that matters
Pour boiling water over the mixture until it thickens. Flour thickens only when its starch is heated and hydrated, so the water must be hot enough to gelatinize the starch. Adding it gradually lets you stop once the sauce reaches the desired thickness and avoids lumps.
Swap the capers
How well each one fits the dish's main ingredients (butter, flour, egg):
- Capersthe original
- Nutmegfits about as well
- Jalapenofits about as well
- Parsleyfits less well
Fit is the average pairing score against butter, flour, egg. 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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