Skip to main content
Sauce

Morcan’s Tartan Sauce—to Mix Mustard

A mustard-based sauce with egg yolk, oil, vinegar, pickles, capers, parsley, and leek.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 11 ingredients
Jump to recipe ↓

Why it works: Mustard and capers match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 624 recipes. Both carry coumarin, which smells sweet, hay. The science ↓

Morcan’s Tartan Sauce—to Mix Mustard

Ingredients

Directions

Make the sauce

  1. In a bowl, combine mustard, salt, and cayenne pepper.

  2. Add the yolk of the raw egg and mix well.

  3. Slowly add sweet oil, stirring until thick.

  4. Thin the mixture with vinegar to your desired consistency.

Add the chopped ingredients

  1. Chop the cucumber pickles, capers, parsley, and leek finely.

  2. Stir the chopped ingredients into the sauce about an hour before serving.

  3. If the sauce is too thick, add cold water to thin it out.

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. Mustard + caperstop 1% of all pairs
    Smell alikestrong
    Cooked together624 recipes

    Shared aroma: coumarin (sweet, hay).

  2. Capers + parsleytop 1% of all pairs
    Smell alikestrong
    Cooked together1,550 recipes

    Shared aroma: coumarin (sweet, hay).

  3. Capers + leektop 1% of all pairs
    Smell alikestrong
    Cooked together27 recipes

    Shared aroma: coumarin (sweet, hay).

  4. Pepper + parsleytop 2% of all pairs
    Smell alikestrong
    Cooked together34,122 recipes

    Shared aroma: 4'-methylacetophenone (bitter almond).

  5. Cucumber + caperstop 3% of all pairs
    Smell alikestrong
    Cooked together303 recipes

    Shared aroma: coumarin (sweet, hay).

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

What each ingredient does

Egg yolk
Emulsifies the oil and mustard so the sauce becomes thick and smooth.
Sweet oil
Provides the fat that, emulsified with the yolk, gives the sauce its body and richness.
Mixed mustard
Helps hold the emulsion together and adds sharp, tangy flavour.
Vinegar
Adds acidity that brightens the sauce and adjusts its consistency.
Cucumber pickles
Add crunch and sour, salty flavour that cut through the richness.
Capers
Add briny, sharp flavour and a pleasant bite.

The step that matters

Slowly add the sweet oil while stirring. Oil added too quickly to the egg yolk and mustard can fail to emulsify and split. Adding it slowly in a thin stream lets the yolk's lecithin bind the droplets, producing a thick, stable sauce.

Swap the leek

How well each one fits the dish's main ingredients (mustard, pepper, egg, vinegar, cucumber, capers, parsley):

  1. Shallotfits better
  2. Horseradishfits better
  3. Lettucefits better
  4. Leekthe original

Fit is the average pairing score against mustard, pepper, egg, vinegar, cucumber, capers, parsley. 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.

More tartar sauce recipes

Hot 3 See all 158 →

You might also like

Mixed MustardMixed Mustard9 recipesWine Sauce (for stewed fruit)Wine Sauce (for stewed fruit)186 recipesCaper SauceCaper Sauce180 recipesBrown SauceBrown Sauce141 recipes