Name: Onion Pickle
Ingredients: small white onions; coarse sea salt; slices of green ginger; mace; good vinegar; green chillies or chilli vinegar (optional)

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 ↓

Onion Pickle

Ingredients

Directions

Place small white onions in a sieve or basket and sprinkle with coarse sea salt.
Let them drain for 24 hours.
Transfer the onions to wide-mouthed bottles.
Add slices of green ginger and a blade or two of mace.
Fill the bottles with good vinegar.
For a warm flavor, add green chillies or chilli vinegar if desired.
Optionally, place the bottles in the sun for one or two days.

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).
Ginger + macetop 11% of all pairs

Smell alikelow

Cooked together2,152 recipes

Shared aroma: alpha-pinene (pine, turpentine).
Onion + vinegartop 14% of all pairs

Smell alikemoderate

Cooked together18,226 recipes

Shared aroma: acetic acid (sour, vinegar).
Onion + macetop 17% of all pairs

Smell alikelow

Cooked together7,078 recipes

Shared aroma: eugenol (clove, spicy).
Ginger + vinegartop 19% of all pairs

Smell alikemoderate

Cooked together5,126 recipes

Shared aroma: isoamyl acetate (banana, pear).