Name: Potato Soup
Ingredients: 3 medium potatoes; 1 pint sweet milk; 1 teaspoon chopped onion; 1 teaspoon chopped celery; 1 teaspoon chopped parsley; 1 tablespoon butter; ½ tablespoon flour; coarse sea salt to taste

Why it works: Celery and parsley match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 6,810 recipes. Both carry 4'-methylacetophenone, which smells bitter almond. The science ↓

Potato Soup

Ingredients

Directions

Prepare the potatoes

Boil the potatoes in salted water until soft.
Drain and mash the cooked potatoes.

Make the soup

In a separate pot, boil the onion, celery, and parsley in the sweet milk.
Pour the boiling milk mixture over the mashed potatoes, stirring quickly.
Pass the mixture through a fine strainer, rubbing as much potato through as possible.
Return the strained soup to the stove and heat 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.

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.

Celery + parsleytop 1% of all pairs

Smell alikestrong

Cooked together6,810 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Potato + oniontop 3% of all pairs

Smell alikemoderate

Cooked together9,023 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Potato + parsleytop 5% of all pairs

Smell alikemoderate

Cooked together2,855 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
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: Provide the starch and body that thicken the soup and give it a smooth, creamy texture.
Sweet milk: Adds moisture and richness, carrying the flavour of the onion, celery and parsley.
Butter: Adds fat for richness and a silky mouthfeel.
Flour: Helps thicken the soup and give it a more stable body.

The step that matters

Pass the mixture through a fine strainer, rubbing as much potato through as possible.. Pushing the cooked potato through the strainer breaks down its starch cells into a smooth purée. Skipping this or leaving the potato in chunks gives a grainy, uneven texture instead of a silky soup.

Swap the onion

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

Carrotfits better
Chivefits better
Leekfits better
Onionthe original

Fit is the average pairing score against potato, milk, celery, parsley, butter, flour. 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.