Name: Potato Soup
Ingredients: 2 lb potatoes; 1 leek (white part only); 1 stick celery; ½ pint cream; 1 pint milk; 1 quart water; 2 oz butter; salt and pepper to taste; 2 oz sago or tapioca

Why it works: Leek and celery match in chemistry and in kitchens. They rank in the top 4% of all ingredient pairs, and cooks put them together in 1,093 recipes. Both carry coumarin, which smells sweet, hay. The science ↓

Potato Soup

Ingredients

Directions

Make the soup

Chop the potatoes, leek, and celery.
Melt butter and add the chopped vegetables.
Cook for about 10 minutes without browning.
Add milk and water.
Boil for about 1 hour until soft enough to pass through a fine sieve.

Finish and serve

Return mixture to heat, adding more milk if needed, sprinkle sago.
Simmer until transparent.
Stir in the cream, ensuring it does not boil.
Serve with fried bread croutons.

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.

Photo for illustrative purposes only · Contact us to use it

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.

Leek + celerytop 4% of all pairs

Smell alikestrong

Cooked together1,093 recipes

Shared aroma: coumarin (sweet, hay).
Celery + peppertop 5% of all pairs

Smell alikestrong

Cooked together16,012 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Potato + leektop 6% of all pairs

Smell alikemoderate

Cooked together30 recipes

Shared aroma: 1-octen-3-ol (mushroom, earthy).
Potato + celerytop 7% of all pairs

Smell alikemoderate

Cooked together2,047 recipes

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

Smell alikemoderate

Cooked together81,283 recipes

Shared aroma: (z)-4-heptenal (biscuit, cream).

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

What each ingredient does

Potatoes: Break down during boiling to thicken the soup and give it a smooth body.
Sago or tapioca: Starch that thickens the soup as it simmers and turns it transparent.
Cream: Adds richness and a silky mouthfeel to the finished soup.
Butter: Fat that softens the vegetables gently and carries flavour before the liquid is added.

The step that matters

Stir in the cream without boiling. Cream can curdle or separate when boiled, and a gentle heat keeps the soup smooth and velvety.

Swap the leek

How well each one fits the dish's main ingredients (potato, celery, cream, milk, butter, pepper):

Carrotfits about as well
Capsicumfits about as well
Leekthe original
Onionfits about as well

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

“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.