Name: Bean Soup
Ingredients: 1 cup common navy beans; 3 pints water; milk or white stock (to thin); coarse sea salt (to taste); black pepper (to taste); thin slices of lemon (for serving)

Why it works: Pepper and lemon match in chemistry and in kitchens. They rank in the top 3% of all ingredient pairs, and cooks put them together in 27,047 recipes. Both carry trans-2-nonenal, which smells cardboard, fatty. The science ↓

Bean Soup

Ingredients

Directions

Prepare the beans

Soak the beans in cold water overnight.

Make the soup

Cook the beans in 3 pints of water until tender.
Pass the cooked beans through a sieve, using the cooking liquid.
Thin the bean paste with milk or white stock until it resembles thin cream.
Season with salt and pepper.

Serve

Place thin slices of lemon in a tureen and pour in the soup.

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.

Pepper + lemontop 3% of all pairs

Smell alikestrong

Cooked together27,047 recipes

Shared aroma: trans-2-nonenal (cardboard, fatty).
Beans + peppertop 11% of all pairs

Smell alikemoderate

Cooked together4,733 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Beans + lemontop 12% of all pairs

Smell alikestrong

Cooked together1,474 recipes

Shared aroma: trans-2-nonenal (cardboard, fatty).
Milk + lemontop 15% of all pairs

Smell alikemoderate

Cooked together19,053 recipes

Shared aroma: 2-nonenal (fatty, green).
Beans + milktop 17% of all pairs

Smell alikemoderate

Cooked together1,266 recipes

Shared aroma: 2,3,5-trimethylpyrazine (cocoa, roasted).

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

Common navy beans: Provide the main body and starch that thicken the soup when cooked and puréed.
Milk or white stock: Thins the bean purée into a smooth, creamy consistency and adds richness.

The step that matters

Pass the cooked beans through a sieve, using the cooking liquid. Sieving breaks down the softened skins and cells to produce a smooth purée. Using the cooking liquid keeps starch and flavour in the soup, so the texture becomes silky rather than grainy.