Name: Tomato and Pea Soup
Ingredients: fat from boiled tongue; 2 quarts empty pea pods; 2 quarts peeled and sliced tomatoes; 2 tablespoons butter; 2 lumps white sugar; pepper to taste

Why it works: Tomato and pepper are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 17,923 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Tomato and Pea Soup

Ingredients

Directions

Make the pea pod broth

Heat the fat from the boiled tongue in a pot until boiling.
Add the empty pea pods.
Boil for 30 minutes.
Strain out the pods.
Set the liquid aside.

Finish the soup

Combine the reserved liquid, peas, and tomatoes in another pot.
Bring to a boil.
Cook for 25 minutes.
Stir in the sugar and butter rolled in flour.
Season with pepper.
Bring to a boil again.
Strain through a colander into the main soup pot.
Simmer for 3 minutes before serving.

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.

Tomato + peppertop 7% of all pairs

Smell alikemoderate

Cooked together17,923 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Butter + sugartop 17% of all pairs

Smell alikemoderate

Cooked together98,233 recipes

Shared aroma: guaiacol (smoky, sweet).
Butter + peppertop 21% of all pairs

Smell alikemoderate

Cooked together85,593 recipes

Shared aroma: trans-2-nonenal (cardboard, fatty).
Tomato + buttertop 22% of all pairs

Smell alikemoderate

Cooked together6,918 recipes

Shared aroma: 3-hexenal (apple, fruity).
Sugar + peppertop 32% of all pairs

Smell alikelow

Cooked together19,401 recipes

Shared aroma: 2-nonenal (fatty, green).

Sugar and pepper barely smell alike, yet cooks put them together in 19,401 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

Empty pea pods: Boiled to make a flavourful liquid that forms the soup base.
Tomatoes: Add acidity, body and a bright, fresh flavour to the soup.
Butter rolled in flour: Enriches the soup and, with the flour, gives it a smoother, slightly thicker body.
White sugar: Adds sweetness that rounds out the acidity of the tomatoes.