Name: Small Pickled Onions
Ingredients: small round onions; salt; milk; water; white wine vinegar or double distilled vinegar; sliced horseradish; white ginger; white pepper

Why it works: Onion and horseradish match in chemistry and in kitchens. They rank in the top 7% of all ingredient pairs, and cooks put them together in 1,784 recipes. Both carry coumarin, which smells sweet, hay. The science ↓

Small Pickled Onions

Ingredients

Directions

Peel the small round onions until they are clear and white.
Boil the onions in a mixture of milk and water with plenty of salt.
Once they boil and look clear, remove them immediately with a slotted spoon.
Lay the onions on a cloth, cover them, and let them cool.
Once cooled and dried, place the onions in a jar or wide-mouthed glass bottle.
In a stone jar, boil the vinegar with sliced horseradish, white ginger, and white pepper.
Pour the cooled vinegar over the onions and cover with a cloth or leather once cold.

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.

Onion + horseradishtop 7% of all pairs

Smell alikestrong

Cooked together1,784 recipes

Shared aroma: coumarin (sweet, hay).
Onion + gingertop 9% of all pairs

Smell alikemoderate

Cooked together7,595 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Horseradish + gingertop 12% of all pairs

Smell alikemoderate

Cooked together676 recipes

Shared aroma: coumarin (sweet, hay).
Onion + white winetop 12% of all pairs

Smell alikemoderate

Cooked together4,535 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Ginger + white peppertop 16% of all pairs

Smell alikelow

Cooked together388 recipes

Shared aroma: eucalyptol (eucalyptus, herbal).

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

Swap the white pepper

How well each one fits the dish's main ingredients (onion, milk, white wine, horseradish, ginger):

Garlicfits better
Turmericfits better
Cinnamonfits better
White pepperthe original

Fit is the average pairing score against onion, milk, white wine, horseradish, ginger. Candidates are from the same food group and used in at least 100 recipes.