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 milk and potatoes
In a pot, bring the milk to a boil with the onion and celery.
Peel the potatoes and boil them for 30 minutes.
Mash and strain
Drain the potatoes and mash them until fine and light.
Add the boiled milk, pepper, and salt to the mashed potatoes.
Rub the mixture through a strainer and serve immediately.
Serve
For an extra touch, add whipped cream when serving.
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.
-
Potato + oniontop 3% of all pairsSmell alikemoderateCooked together9,023 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Celery + peppertop 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).
-
Milk + buttertop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
-
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 mashes into the body and thickness of the soup.
- Milk
- Liquid that gives the soup its creamy, smooth texture.
- Onion
- Adds savory aroma that flavors the milk as it heats.
- Celery
- Adds a mild, vegetal aroma that infuses the milk.
The step that matters
Mash the potatoes until fine and light. Overworking boiled potatoes releases excess starch, which makes the mash gluey rather than light. Mashing gently and adding the warm milk keeps the texture smooth and airy before straining.
Swap the celery
How well each one fits the dish's main ingredients (milk, potato, onion, butter, pepper, cream):
- Garlicfits about as well
- Parsleyfits about as well
- Thymefits about as well
- Celerythe original
Fit is the average pairing score against milk, potato, onion, butter, pepper, cream. 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.
More potato soup recipes
You might also like
The free Flavor Lab newsletter: one surprising pairing a week and the molecular reason it works, in 60 seconds. No spam, unsubscribe anytime.
Prefer an account? Create a free account to save pairings and unlock the full chemistry.

Potato Croquettes255 recipes
Cream of Celery Soup113 recipes
Potato Rolls78 recipes
Potato Chips53 recipes