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
Make the soup base
Scald the milk in a double boiler.
Add the mashed potato to the scalded milk and cook for 10 minutes.
Flavour and serve
Melt the butter in a pan and brown the onion in it.
Remove the onion and add the butter to the soup.
Season with salt and pepper, then strain through a strainer.
Reheat the soup and serve with croutons.
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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Milk + buttertop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
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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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Milk + potatotop 9% of all pairsSmell alikemoderateCooked together3,611 recipes
Shared aroma: (e,z)-2,6-nonadienal (cucumber, melon).
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Pepper + oniontop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Milk
- Forms the liquid base and adds creaminess from its milk fats and proteins.
- Mashed potato
- Releases starch as it cooks, thickening the soup and giving it body.
- Butter
- Adds fat that carries flavour and gives a rich, smooth mouthfeel.
- Onion
- Browning in butter builds a savoury, aromatic flavour base for the soup.
The step that matters
Cooking the potato in the milk. Mashed potato can scorch on the base of the pan or form lumps in hot milk. Stirring often over gentle heat keeps the starch dispersed, so the soup thickens evenly and stays smooth.
Swap the onion
How well each one fits the dish's main ingredients (milk, potato, pepper, butter):
- Capsicumfits better
- Asparagusfits about as well
- Tomatofits about as well
- Onionthe original
Fit is the average pairing score against milk, potato, pepper, butter. 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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