Skip to main content
Baking

To Pickle Onions

A method for pickling onions in vinegar with mustard seeds, mace, capsicum, and optional salad oil.

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 ↓

To Pickle Onions

Ingredients

Directions

Prepare

  1. Remove the outer skin from the onions and trim the tops and bottoms.

Pickle

  1. Place the onions in bottles and add enough vinegar to cover them.

  2. Add a few mustard seeds, a blade of mace, and a capsicum to each bottle.

  3. Optionally, add a spoonful of salad oil to each bottle to keep the onions white.

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. Mustard + capsicumtop 7% of all pairs
    Smell alikestrong
    Cooked together6,274 recipes

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

  4. Onion + capsicumtop 9% of all pairs
    Smell alikemoderate
    Cooked together23,390 recipes

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

  5. Vinegar + capsicumtop 11% of all pairs
    Smell alikemoderate
    Cooked together10,160 recipes

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

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

What each ingredient does

Onions
Form the main body of the pickle, softening slightly while taking on the vinegar flavour.
Vinegar
Acidity that preserves the onions and gives them their sharp, tangy flavour.
Mustard seeds
Add a sharp, aromatic pungency that infuses into the pickling liquid.

The step that matters

Covering the onions fully with vinegar. Onions exposed above the liquid can spoil and discolour, and the acid only preserves and seasons the parts it touches. Keeping every piece submerged gives an even pickle.

Swap the mace

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

  1. Garlicfits better
  2. Tarragonfits better
  3. Capersfits better
  4. Macethe original

Fit is the average pairing score against onion, vinegar, mustard, capsicum. 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 pickled onions recipes

and Apples 3and Cucumbers 3 See all 163 →

You might also like

Delicate CakeDelicate Cake246 recipesBoiled FrostingBoiled Frosting69 recipesCitron CakeCitron Cake68 recipesScotch CakeScotch Cake63 recipes