Name: Pickled Walnuts
Ingredients: green walnut husks; coarse sea salt; cold unboiled vinegar; whole peppers

Why it works: Walnut and pepper are a kitchen classic. They rank in the top 13% of all ingredient pairs, and cooks put them together in 3,039 recipes. Both carry 2-nonenal, which smells fatty, green. The science ↓

Pickled Walnuts

Ingredients

green walnut husks
coarse sea salt
cold unboiled vinegar
whole peppers

Directions

Gather green walnut husks early in August.
Sprinkle coarse sea salt over the husks until they turn black.
Once black, pour cold unboiled vinegar over them in jars.
Add whole peppers to each jar.

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.

Walnut + peppertop 13% of all pairs

Smell alikemoderate

Cooked together3,039 recipes

Shared aroma: 2-nonenal (fatty, green).
Vinegar + peppertop 14% of all pairs

Smell alikemoderate

Cooked together27,814 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Walnut + vinegartop 22% of all pairs

Smell alikemoderate

Cooked together1,769 recipes

Shared aroma: sotolon (curry, maple).