Why it works: Celery and parsley match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 6,810 recipes. Both carry 4'-methylacetophenone, which smells bitter almond. The science ↓
Potato Soup
Ingredients
Directions
Prepare the vegetables
Peel, wash, and cut the potatoes into pieces.
Peel and roughly chop the onion.
Prepare and cut the celery into small pieces.
Make the soup
Cook the vegetables in 3 pints of water until soft.
Rub the mixture through a sieve and return it to the saucepan.
Add the milk, butter, and seasoning, then bring to a boil.
If the soup is too thick, add more water.
Mix in the parsley just before 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.
-
Celery + parsleytop 1% of all pairsSmell alikestrongCooked together6,810 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
Parsley + peppertop 2% of all pairsSmell alikestrongCooked together34,122 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
-
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).
-
Celery + peppertop 5% of all pairsSmell alikestrongCooked together16,012 recipes
Shared aroma: 4'-methylacetophenone (bitter almond).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Potatoes
- Break down to give the soup its body and thick, smooth texture.
- Butter
- Adds fat and richness, rounding out the flavour and mouthfeel of the soup.
- Milk
- Adds creaminess and a softer, rounder body to the soup.
- Spanish onion
- Contributes sweetness and savoury aroma as it softens in the cooking water.
The step that matters
Rub the mixture through a sieve. Pressing the cooked vegetables through a sieve breaks them into fine particles, which gives the soup a smooth texture. Leftover lumps or fibres from the celery and onion will remain if the mixture is not pushed through thoroughly.
Swap the onion
How well each one fits the dish's main ingredients (potato, celery, milk, butter, parsley, pepper):
- Carrotfits better
- Capsicumfits better
- Chivefits better
- Onionthe original
Fit is the average pairing score against potato, celery, milk, butter, parsley, 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.
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