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 No. I
Ingredients
Directions
Cook the potatoes
Wash and peel the potatoes, then cook them in boiling salted water until tender.
Drain and mash the potatoes in the same kettle.
Add hot water, salt, pepper, and celery salt to the mashed potatoes.
Make the soup
Scald the milk and cook the onion in it, then remove the onion.
Add the scalded milk to the soup.
Mix the flour with a little cold water and stir it into the boiling soup.
Let the soup boil for three to four minutes, stirring constantly.
Add the butter just before removing from heat; the butter can be omitted if desired.
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.
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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Pepper + celerytop 5% of all pairsSmell alikestrongCooked together16,012 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
Potato + celerytop 7% of all pairsSmell alikemoderateCooked together2,047 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
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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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Celery + oniontop 7% of all pairsSmell alikemoderateCooked together18,518 recipes
Shared aroma: guaiacol (smoky, sweet).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Potatoes
- Starch that breaks down into a thick, creamy body when mashed.
- Milk
- Adds richness and creaminess, softening the soup's flavour and texture.
- Flour
- Thickens the soup as its starch swells when boiled with liquid.
- Butter
- Adds fat for a smoother mouthfeel and rounder flavour.
The step that matters
Boiling after adding the flour. Flour thickens only when its starch is heated in liquid, so the soup must boil while stirred constantly. Stirring prevents lumps from forming as the starch swells.
Swap the celery
How well each one fits the dish's main ingredients (potato, milk, pepper, onion, flour, butter):
- Parsleyfits better
- Thymefits better
- Garlicfits better
- Celerythe original
Fit is the average pairing score against potato, milk, pepper, onion, flour, 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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