Name: Pickled Onions
Ingredients: 7 lbs silver-skinned onions; 4 oz pickling spice; Malt vinegar

Why it works: Onion and vinegar are a kitchen classic. They rank in the top 14% of all ingredient pairs, and cooks put them together in 18,226 recipes. Both carry acetic acid, which smells sour, vinegar. The science ↓

Pickled Onions

Ingredients

7 lbs silver-skinned onions
4 oz pickling spice
Malt vinegar

Directions

Peel the onions carefully and soak them in saltwater until finished.
Drain the water and place the onions into dry, wide-mouthed bottles.
Boil the pickling spice in some vinegar; let it cool slightly.
Pour a little of the spice-infused vinegar into each bottle, then fill the bottles with more vinegar.
Cover the bottles with paper and seal them tightly.
Let the pickles sit for one month before using.

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 + vinegartop 14% of all pairs

Smell alikemoderate

Cooked together18,226 recipes

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

Smell alikemoderate

Cooked together365 recipes

Shared aroma: beta-damascenone (apple, rose).
Onion + malttop 23% of all pairs

Smell alikelow

Cooked together180 recipes

Shared aroma: guaiacol (smoky, sweet).