Name: Onion Pickles
Ingredients: white onions (small, not larger than a large olive); brine (strong enough to float an egg); red peppers; pieces of horseradish; whole black pepper; allspice; mace; vinegar

Why it works: Horseradish and allspice match in chemistry and in kitchens. They rank in the top 4% of all ingredient pairs, and cooks put them together in 654 recipes. Both carry coumarin, which smells sweet, hay. The science ↓

Onion Pickles

Ingredients

Directions

Peel the white onions and soak them in brine for one week, changing the brine daily.
After a week, soak the onions in cold water for one day and drain well.
Pack the onions into jars with red peppers, pieces of horseradish, whole black pepper, allspice, and mace.
Heat the vinegar to boiling point and pour it over the packed onions. Repeat this process twice.

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.

Horseradish + allspicetop 4% of all pairs

Smell alikestrong

Cooked together654 recipes

Shared aroma: coumarin (sweet, hay).
Pepper + allspicetop 5% of all pairs

Smell alikestrong

Cooked together6,395 recipes

Shared aroma: estragole (anise, licorice).
Onion + horseradishtop 7% of all pairs

Smell alikestrong

Cooked together1,784 recipes

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

Smell alikemoderate

Cooked together3,189 recipes

Shared aroma: methyleugenol (clove, spice).
Onion + olivetop 8% of all pairs

Smell alikemoderate

Cooked together29,779 recipes

Shared aroma: 2,4-decadienal (seaweed).

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

Swap the mace

How well each one fits the dish's main ingredients (onion, olive, egg, pepper, horseradish, allspice, vinegar):

Thymefits better
Tarragonfits better
Parsleyfits better
Macethe original

Fit is the average pairing score against onion, olive, egg, pepper, horseradish, allspice, vinegar. Candidates are from the same food group and used in at least 100 recipes.