Why it works: Pepper and parsley match in chemistry and in kitchens. They rank in the top 2% of all ingredient pairs, and cooks put them together in 34,122 recipes. Both carry 4'-methylacetophenone, which smells bitter almond. The science ↓
Potato Soup
Ingredients
Directions
Prepare the potatoes
Peel the potatoes and place them in a saucepan with the onion.
Cover with boiling water and cook over high heat for 30 minutes.
After 30 minutes, drain the water, saving it for later.
Make the milk thickener
Reserve ½ cup of cold milk and heat the remaining milk in a double boiler.
Mix the flour with the cold milk and stir into the boiling milk.
Finish the soup
Mash the potatoes and onion until smooth, then gradually mix in the reserved water.
Pass the mixture through a sieve and return it to the heat.
Add salt and pepper, whisk for 3 minutes, then gradually stir in the boiling milk.
Add the butter or butter substitute and minced parsley, and serve immediately.
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.
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Pepper + parsleytop 2% of all pairsSmell alikestrongCooked together34,122 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
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Potato + oniontop 3% of all pairsSmell alikemoderateCooked together9,023 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Potato + parsleytop 5% of all pairsSmell alikemoderateCooked together2,855 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
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Butter + milktop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
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Onion + parsleytop 9% of all pairsSmell alikemoderateCooked together25,843 recipes
Shared aroma: 2,4-decadienal (seaweed).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Potatoes
- Form the body of the soup as they break down into a smooth purée.
- Milk
- Provides the liquid base and creamy texture of the soup.
- Flour
- Thickens the milk so the soup becomes smooth and body-rich.
- Butter or butter substitute
- Adds fat for richness and a silky mouthfeel.
The step that matters
Stirring the flour into the milk. Flour mixed into hot liquid without first being blended with cold milk forms lumps, because starch granules clump before they can disperse. Mixing the flour with cold milk first lets it disperse evenly, so the thickened soup stays smooth when it is stirred into the boiling milk.
Swap the onion
How well each one fits the dish's main ingredients (potato, pepper, butter, parsley, milk, flour):
- Carrotfits better
- Chivefits better
- Shallotfits better
- Onionthe original
Fit is the average pairing score against potato, pepper, butter, parsley, milk, 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.
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