Why it works: Potato and onion are a kitchen classic. They rank in the top 3% of all ingredient pairs, and cooks put them together in 9,023 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Potato Soup
Ingredients
Directions
Cook the soup
Slice the potatoes and add them to the boiling water.
Once the potatoes are cooked, add the milk and sliced onion.
Finish and serve
Thicken the soup just before serving by mixing the egg with enough flour to moisten.
Season with pepper and coarse sea salt to taste.
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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Potato + oniontop 3% of all pairsSmell alikemoderateCooked together9,023 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Potato + peppertop 9% of all pairsSmell alikemoderateCooked together8,305 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Potato + milktop 9% of all pairsSmell alikemoderateCooked together3,611 recipes
Shared aroma: (e,z)-2,6-nonadienal (cucumber, melon).
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Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Milk + flourtop 14% of all pairsSmell alikelowCooked together78,219 recipes
Shared aroma: isobutyraldehyde (malty, green).
Milk and flour barely smell alike, yet cooks put them together in 78,219 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
- Potatoes
- Break down as they cook, giving the soup body and a starchy, creamy base.
- Milk
- Adds richness and a creamy texture to the broth.
- Egg
- Thickens the soup when mixed with flour and stirred in near the end.
- Flour
- Works with the egg to thicken the soup, binding it to a smoother consistency.
- Onion
- Adds savory aroma and a mild sweetness as it softens in the soup.
The step that matters
Thickening with egg and flour. Adding the egg and flour mixture to hot soup can cause lumps or curdling. Moisten the flour fully first, then stir it in just before serving, and keep the soup from boiling hard so the egg thickens smoothly.
Swap the onion
How well each one fits the dish's main ingredients (potato, milk, egg, flour, pepper):
- Capsicumfits better
- Asparagusfits better
- Chivefits better
- Onionthe original
Fit is the average pairing score against potato, milk, egg, flour, 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.
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