Skip to main content
Main

French Mustard

A mustard condiment made by steeping onion in vinegar, then adding cayenne, salt, sugar, and mustard seeds, and boiling.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 6 ingredients
Jump to recipe ↓

Why it works: Onion and mustard match in chemistry and in kitchens. They rank in the top 6% of all ingredient pairs, and cooks put them together in 9,259 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

French Mustard

Ingredients

Directions

Prepare the onion

  1. Slice the onion and place it in a bowl.

  2. Cover the onion with vinegar and let it sit for two days.

  3. After two days, pour off the vinegar.

Make the mustard

  1. Add cayenne pepper, salt, sugar, and enough mustard to thicken the mixture.

  2. Heat the mixture on the stove until it boils.

  3. Allow it to cool before using.

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.

  1. Onion + mustardtop 6% of all pairs
    Smell alikestrong
    Cooked together9,259 recipes

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

  2. Vinegar + mustardtop 7% of all pairs
    Smell alikemoderate
    Cooked together14,067 recipes

    Shared aroma: isobutyraldehyde (malty, green).

  3. Pepper + mustardtop 9% of all pairs
    Smell alikemoderate
    Cooked together15,430 recipes

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

  4. Onion + peppertop 11% of all pairs
    Smell alikemoderate
    Cooked together68,474 recipes

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

  5. Onion + vinegartop 14% of all pairs
    Smell alikemoderate
    Cooked together18,226 recipes

    Shared aroma: acetic acid (sour, vinegar).

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

What each ingredient does

Onion
Soaked in vinegar, it softens and mellows, adding savory depth to the mustard.
Vinegar
Acidity that softens the onion and gives the mustard a sharp, tangy bite.
Mustard
Provides the base flavor and thickens the mixture into a spreadable consistency.
Sugar
Balances the sharpness of the vinegar and mustard with a touch of sweetness.

The step that matters

Heating the mixture until it boils. Boiling helps blend the flavors and gives the mixture a stable, thicker texture. Heating too little may leave it thin and raw-tasting, while the cayenne and mustard flavors can turn harsh if overheated.

Swap the onion

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

  1. Horseradishfits better
  2. Capsicumfits better
  3. Radishfits better
  4. Onionthe original

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

You might also like

Tomato SoupTomato Soup526 recipesBrown BreadBrown Bread461 recipesMutton BrothMutton Broth292 recipesYorkshire PuddingYorkshire Pudding264 recipes