Name: Onions
Ingredients: small button onions; milk; water; coarse sea salt; cold white wine vinegar; whole white pepper; ginger; mace; slices of horseradish

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 ↓

Onions

Ingredients

Directions

Peel small button onions and soak them in a mixture of milk and water with plenty of coarse sea salt.
Bring the mixture to a boil, then strain the onions and wipe them dry.
Place the onions into glasses.
In a separate pot, boil cold white wine vinegar with whole white pepper, ginger, mace, and slices of horseradish.
Pour the vinegar mixture over the onions and cover them with bladder and leather.

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).
White pepper + macetop 9% of all pairs

Smell alikemoderate

Cooked together1,695 recipes

Shared aroma: myrcene (balsamic, herbaceous).
White wine + vinegartop 11% of all pairs

Smell alikemoderate

Cooked together1,776 recipes

Shared aroma: beta-damascenone (apple, rose).
Ginger + macetop 11% of all pairs

Smell alikelow

Cooked together2,152 recipes

Shared aroma: alpha-pinene (pine, turpentine).

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, vinegar, ginger, mace, horseradish):

Clovefits better
Allspicefits better
Cinnamonfits better
White pepperthe original

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