Name: Pickled Onions
Ingredients: small silver-skinned onions; brine (enough to float an egg); horseradish (chopped); cinnamon bark; cloves; cayenne pepper; brown sugar; vinegar

Why it works: Cinnamon and clove match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 14,189 recipes. Both carry ethyl cinnamate, which smells sweet, balsamic. The science ↓

Pickled Onions

Ingredients

Directions

Prepare the onions

Peel the outer skins from the onions using a silver knife until they are clean and white.
Soak the onions in brine for three days.
Drain the onions and place them in a jar in layers, starting with a layer of onions three inches deep.

Spice and pickle

Sprinkle each layer with chopped horseradish, cinnamon bark, cloves, and cayenne pepper.
Use ½ teaspoon cayenne pepper, 2 tablespoons chopped horseradish, 2 tablespoons cloves, and 4 teaspoons cinnamon bark for every gallon of pickles.
Bring the vinegar to a boiling point and add 1 quart of brown sugar for every gallon of vinegar.
Pour the hot vinegar mixture over the onions in the jar.

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.

Cinnamon + clovetop 1% of all pairs

Smell alikestrong

Cooked together14,189 recipes

Shared aroma: ethyl cinnamate (sweet, balsamic).
Clove + peppertop 5% of all pairs

Smell alikestrong

Cooked together17,451 recipes

Shared aroma: ethyl octanoate (fruity, wine).
Horseradish + cinnamontop 6% of all pairs

Smell alikestrong

Cooked together515 recipes

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

Smell alikestrong

Cooked together1,784 recipes

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

Smell alikestrong

Cooked together1,245 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

Small silver-skinned onions: Main vegetable; soaking and pickling mellow its sharp bite and give it a tender texture.
Vinegar: Acid that preserves the onions and gives the pickle its sharp tang.
Brown sugar: Adds sweetness that balances the sharpness of the vinegar.
Horseradish: Adds sharp, pungent heat and aroma to the jar.
Cloves: Adds warm, aromatic spice flavour to the pickling liquid.

Swap the onion

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

Mustardfits better
Capsicumfits better
Beetrootfits better
Onionthe original

Fit is the average pairing score against egg, horseradish, cinnamon, clove, pepper, sugar, 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.