Name: Mock Turtle Soup
Ingredients: 1 quart black or red beans; 1 quart soup stock (fat removed); pepper to taste; coarse sea salt to taste; 1 hard boiled egg, chopped finely; 1 sliced lemon

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 ↓

Mock Turtle Soup

Ingredients

Directions

Prepare the beans

Boil the beans in water all day.
Strain the beans through a colander, then through a fine sieve.

Make the soup

The next day, add the soup stock, pepper, and salt to the beans.
Boil for one hour.

Serve

When ready to serve, add the chopped hard boiled egg and sliced lemon.

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).
Egg + lemontop 19% of all pairs

Smell alikelow

Cooked together44,316 recipes

Shared aroma: (e,e)-2,4-decadienal (fatty, deep fried).
Beans + eggtop 32% of all pairs

Smell alikemoderate

Cooked together2,030 recipes

Shared aroma: 1-octen-3-ol (mushroom, earthy).

Egg and lemon barely smell alike, yet cooks put them together in 44,316 recipes: they work on texture and structure more than aroma.

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

What each ingredient does

Black or red beans: Form the body and thick base of the soup once boiled and strained.
Soup stock: Adds savory liquid and depth of flavor to the bean base.
Hard boiled egg: Adds finely chopped texture and a mild, rich note to the soup.
Lemon: Adds bright acidity that lifts the flavor of the rich soup.