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
Make the sauce
In a saucepan, melt the butter over medium heat.
Add salt and white pepper to taste.
Once melted, gradually stir in the warm broth (or water) and flour until well mixed.
Do not let the mixture boil; keep it on moderate heat.
Finish and serve
In a separate bowl, mix the pounded capers, egg yolk, and vinegar.
Remove the sauce from heat and stir in the caper mixture.
Serve immediately.
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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Capers + vinegartop 16% of all pairsSmell alikemoderateCooked together1,453 recipes
Shared aroma: isobutyraldehyde (malty, green).
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
- Forms the fat base of the sauce and carries its rich flavour.
- Flour
- Thickens the warm broth into a smooth, coating sauce.
- Egg yolk
- Adds richness and helps emulsify and thicken the sauce.
- Pounded capers
- Provide the sharp, briny flavour that defines the sauce.
- Vinegar
- Adds acidity that brightens the buttery sauce.
The step that matters
Keep the sauce from boiling. Egg yolk in the sauce can curdle or scramble if it gets too hot, and boiling can break the emulsion. Keeping moderate heat and removing the pan before adding the caper mixture protects the smooth texture.
Swap the white pepper
How well each one fits the dish's main ingredients (butter, flour, capers, egg, vinegar):
- Tarragonfits better
- Parsleyfits better
- Nutmegfits better
- White pepperthe original
Fit is the average pairing score against butter, flour, capers, egg, vinegar. 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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