Name: Pepper Sauce
Ingredients: ½ cup chopped onions; 1 tablespoon mustard; 1 tablespoon sugar; 1 tablespoon horseradish; 1 teaspoon black pepper; 6 green peppers; 6 red peppers; salt to taste; vinegar to fill

Why it works: Mustard and horseradish match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 1,832 recipes. Both carry coumarin, which smells sweet, hay. The science ↓

Pepper Sauce

Ingredients

Directions

Mix

Combine chopped onions, mustard, sugar, horseradish, black pepper, green peppers, and red peppers in a bowl.
Season with salt to taste.

Bottle and store

Transfer the mixture to a pint bottle.
Fill the bottle with vinegar.
Seal and store in a cool place.

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.

Mustard + horseradishtop 1% of all pairs

Smell alikestrong

Cooked together1,832 recipes

Shared aroma: coumarin (sweet, hay).
Onion + mustardtop 6% of all pairs

Smell alikestrong

Cooked together9,259 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Onion + horseradishtop 7% of all pairs

Smell alikestrong

Cooked together1,784 recipes

Shared aroma: coumarin (sweet, hay).
Mustard + vinegartop 7% of all pairs

Smell alikemoderate

Cooked together14,067 recipes

Shared aroma: isobutyraldehyde (malty, green).
Mustard + peppertop 9% of all pairs

Smell alikemoderate

Cooked together15,430 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

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

What each ingredient does

Green peppers: Provide the main bulk and fresh, vegetal flavor of the sauce.
Red peppers: Add bulk and a sweeter, rounder pepper flavor to the sauce.
Vinegar: Supplies the acidity that gives the sauce its sharp taste and helps preserve it.
Horseradish: Contributes sharp, pungent heat that gives the sauce its bite.
Mustard: Adds a tangy, pungent note that rounds out the heat.
Sugar: Adds sweetness that balances the sharpness of the vinegar.

Swap the onion

How well each one fits the dish's main ingredients (mustard, sugar, horseradish, pepper, vinegar):

Radishfits better
Beetrootfits better
Shallotfits better
Onionthe original

Fit is the average pairing score against mustard, sugar, horseradish, pepper, 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.