Name: Clear Celery Soup
Ingredients: 1 large head of celery or 2 small ones; 1 large Spanish onion; 2 oz. of butter; pepper to taste; coarse sea salt to taste; 1 blade of mace; 4 pints of water; 1 oz. of vermicelli, sago, or Italian paste; sippets of crisp toast or plain rusks

Why it works: Celery and pepper match in chemistry and in kitchens. They rank in the top 5% of all ingredient pairs, and cooks put them together in 16,012 recipes. Both carry 4'-methylacetophenone, which smells bitter almond. The science ↓

Clear Celery Soup

Ingredients

Directions

Prepare the base

Chop the onion and fry it brown in the butter in a saucepan.
Add 4 pints of water, chopped celery, mace, pepper, and salt.
Cook until the celery is soft.
Drain the liquid from the vegetables.
Return the liquid to the saucepan.

Finish and serve

Bring to a boil.
Add the vermicelli, sago, or Italian paste.
Cook until the pasta is soft.
Serve with crisp toast or plain rusks.

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.

Celery + peppertop 5% of all pairs

Smell alikestrong

Cooked together16,012 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Celery + oniontop 7% of all pairs

Smell alikemoderate

Cooked together18,518 recipes

Shared aroma: guaiacol (smoky, sweet).
Onion + peppertop 11% of all pairs

Smell alikemoderate

Cooked together68,474 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Onion + buttertop 15% of all pairs

Smell alikemoderate

Cooked together42,912 recipes

Shared aroma: decanal (soap, orange peel).
Pepper + macetop 16% of all pairs

Smell alikelow

Cooked together12,257 recipes

Shared aroma: myristicin (spice, warm).

Pepper and mace barely smell alike, yet cooks put them together in 12,257 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

Onion: Frying in butter until brown adds sweetness and savoury depth to the broth.
Celery: Simmered in the water to give the soup its main flavour and body.
Butter: Carries the onion's flavour and browns it, adding richness to the soup.
Vermicelli, sago, or italian paste: Adds starch and body to the soup as it cooks in the broth.