Name: Pickled Onions
Ingredients: small onions of equal size; salt; vinegar; whole cloves; mace

Why it works: Clove and mace are a kitchen classic. They rank in the top 6% of all ingredient pairs, and cooks put them together in 8,400 recipes. Both carry methyleugenol, which smells clove, spice. The science ↓

Pickled Onions

Ingredients

Directions

The book gives no oven temperature. The 380°F (193°C) in the steps was added when the recipe was transcribed, as a starting point.

Select small onions that are perfectly sound and of equal size.
Peel the onions and scald them in salt water until tender.
Drain the onions and place them into glass jars.
Heat vinegar to 380°F (193°C) and mix in whole cloves and mace.
Pour the hot vinegar over the onions, distributing the spices among the jars.
Seal the jars air-tight after pouring the vinegar over the onions.

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.

Clove + macetop 6% of all pairs

Smell alikelow

Cooked together8,400 recipes

Shared aroma: methyleugenol (clove, spice).
Onion + clovetop 13% of all pairs

Smell alikemoderate

Cooked together16,901 recipes

Shared aroma: 2-nonanone (fruity, floral).
Onion + vinegartop 14% of all pairs

Smell alikemoderate

Cooked together18,226 recipes

Shared aroma: acetic acid (sour, vinegar).
Vinegar + clovetop 15% of all pairs

Smell alikemoderate

Cooked together10,386 recipes

Shared aroma: isobutyraldehyde (malty, green).
Onion + macetop 17% of all pairs

Smell alikelow

Cooked together7,078 recipes

Shared aroma: eugenol (clove, spicy).