Name: To Pickle Onions
Ingredients: very small onions; salt; water; white wine vinegar; salad oil; blades of mace; slices of ginger or nutmeg

Why it works: Onion and ginger are a kitchen classic. They rank in the top 9% of all ingredient pairs, and cooks put them together in 7,595 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

To Pickle Onions

Ingredients

Directions

Cut off the stems of the small onions and peel off the outer skin.
Soak the onions in a mixture of salt and water for 9 days, stirring daily and changing the salt and water every 2 days.
After 9 days, scald the onions in boiling salt water and let them cool.
Drain the onions on a sieve and wipe them dry.
Insert a clove into the top of each onion and place them in wide-mouthed bottles.
Add blades of mace and slices of ginger or nutmeg among the onions.
Fill the bottles with the best white wine vinegar and top with a spoonful of salad oil.
Cork the bottles tightly.

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 + gingertop 9% of all pairs

Smell alikemoderate

Cooked together7,595 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
White wine + vinegartop 11% of all pairs

Smell alikemoderate

Cooked together1,776 recipes

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

Smell alikelow

Cooked together2,152 recipes

Shared aroma: alpha-pinene (pine, turpentine).
Onion + white winetop 12% of all pairs

Smell alikemoderate

Cooked together4,535 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Onion + vinegartop 14% of all pairs

Smell alikemoderate

Cooked together18,226 recipes

Shared aroma: acetic acid (sour, vinegar).

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, white wine, vinegar, ginger):

Garlicfits better
Clovefits better
Thymefits better
Macethe original

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