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
Cook the potatoes
Pare the potatoes.
Place them in a saucepan with the onion.
Cover with boiling water.
Cook over high heat for 30 minutes.
Pour off the cooking water, saving it for later.
Mash the potatoes and onion until light and fine.
Rub the mixture through a sieve.
Make the thickened milk
Reserve ½ cup of cold milk.
Heat the remaining milk in a double boiler.
Mix the flour with the cold milk.
Stir into the boiling milk.
Combine and serve
Gradually mix in the reserved water.
Return it to the heat.
Add salt and pepper.
Whisk for 3 minutes.
Gradually beat in the boiling milk.
Add butter and parsley.
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).
-
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
- Their starch and fibre, once mashed and sieved, give the soup its body and smooth texture.
- Milk
- Forms the creamy liquid base of the soup and carries the flavour.
- Flour
- Its starch swells in the hot milk and thickens the soup.
- Butter
- Adds fat for richness and a smooth, velvety mouthfeel.
- Onion
- Adds savoury aroma and flavour that infuses into the potatoes as they cook.
The step that matters
Stirring the flour mixture into boiling milk. Dry flour clumps when it meets hot liquid because its outer starch gels before the inside wets. Mixing the flour into cold milk first disperses the starch, and stirring as it heats lets the granules swell evenly and thicken the soup smoothly.
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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