Name: Horseradish Sauce
Ingredients: 1 onion; 1 teaspoon grated horseradish; 1-2 tablespoons essence of anchovies; butter; lemon-pickle or lemon-juice; vinegar (optional)

Why it works: Onion and horseradish match in chemistry and in kitchens. They rank in the top 7% of all ingredient pairs, and cooks put them together in 1,784 recipes. Both carry coumarin, which smells sweet, hay. The science ↓

Horseradish Sauce

Ingredients

Directions

Stew the onion in a little fish stock until it becomes soft.
Add the grated horseradish and essence of anchovies, then mix well.
Heat the mixture over a fire and thicken it with butter.
Finish with a spoonful of lemon-pickle or lemon-juice, or substitute vinegar if desired.

Recipe from a historical cookbook (Internet Archive).

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.

Onion + horseradishtop 7% of all pairs

Smell alikestrong

Cooked together1,784 recipes

Shared aroma: coumarin (sweet, hay).
Horseradish + lemontop 9% of all pairs

Smell alikestrong

Cooked together1,155 recipes

Shared aroma: coumarin (sweet, hay).
Horseradish + vinegartop 12% of all pairs

Smell alikemoderate

Cooked together2,609 recipes

Shared aroma: isobutyraldehyde (malty, green).
Onion + vinegartop 14% of all pairs

Smell alikemoderate

Cooked together18,226 recipes

Shared aroma: acetic acid (sour, vinegar).
Onion + buttertop 15% of all pairs

Smell alikemoderate

Cooked together42,912 recipes

Shared aroma: decanal (soap, orange peel).

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

Onion: Softens into the base, adding body and mild sweetness to the sauce.
Butter: Enriches the sauce and thickens it as it heats, giving a smooth, rounded texture.
Grated horseradish: Supplies the sharp, pungent heat that defines the sauce.
Essence of anchovies: Adds deep savoury flavour that rounds out the sharpness of the horseradish.
Lemon-pickle or lemon-juice: Adds acidity that brightens the sauce and balances its richness.

Swap the lemon

How well each one fits the dish's main ingredients (onion, horseradish, butter, vinegar):

Avocadofits better
Plumfits about as well
Mangofits about as well
Lemonthe original

Fit is the average pairing score against onion, horseradish, butter, 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.