Name: Split Pea Soup
Ingredients: 1 cup dried split peas; 8 cups cold water; 2-inch cube fat salt pork; 1 tablespoon chopped onion; 2 tablespoons flour; 1 tablespoon salt; ¼ teaspoon pepper; 2 tablespoons butter; 2 cups milk

Why it works: Butter and milk are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 81,283 recipes. Both carry (z)-4-heptenal, which smells biscuit, cream. The science ↓

Split Pea Soup

Ingredients

Directions

Pick over and wash the peas; soak overnight in 1 quart of cold water with 3 tablespoons of baking soda.
Drain the peas, then add 8 cups of cold water, pork, and onion; simmer until soft, about 3 to 4 hours.
Rub the mixture through a sieve.
Finish according to your preferred method.

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.

Butter + milktop 7% of all pairs

Smell alikemoderate

Cooked together81,283 recipes

Shared aroma: (z)-4-heptenal (biscuit, cream).
Pork + oniontop 10% of all pairs

Smell alikemoderate

Cooked together18,214 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Onion + peppertop 11% of all pairs

Smell alikemoderate

Cooked together68,474 recipes

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

Smell alikelow

Cooked together124,287 recipes

Shared aroma: isobutyraldehyde (malty, green).
Pork + milktop 12% of all pairs

Smell alikemoderate

Cooked together4,386 recipes

Shared aroma: 4-heptenal (creamy, biscuit).

Flour and butter barely smell alike, yet cooks put them together in 124,287 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

Swap the peas

How well each one fits the dish's main ingredients (pork, onion, flour, pepper, butter, milk):

Beansfits better
Sesamefits better
Chestnutfits better
Peasthe original

Fit is the average pairing score against pork, onion, flour, pepper, butter, milk. Candidates are from the same food group and used in at least 100 recipes.