Why it works: Potato and leek work together. They rank in the top 6% of all ingredient pairs, and cooks put them together in 30 recipes. Both carry 1-octen-3-ol, which smells mushroom, earthy. The science ↓
Milk Soup
Ingredients
Directions
Prepare the vegetables
Bring 2 quarts of water to a boil in a large saucepan.
Wash, scrub, peel, and quarter the potatoes.
Trim the green tops from the leeks, wash them, and chop them.
Make the soup
Melt 2 oz of butter in a stewpan and add the vegetables; sweat them for 5 minutes.
Pour the vegetables and butter into the boiling water.
Add 1/4 oz of salt and pepper to taste.
Boil until the mixture is soft enough to mash.
Strain the soup through a colander or wire sieve.
Rub the vegetables through the colander with a wooden spoon.
Return the pulp and soup to the saucepan.
Add 1 pint of milk and bring to a boil.
Gradually sprinkle in 3 tablespoons of crushed tapioca while stirring continuously.
Let it boil gently for 15 minutes.
Serve
Serve the soup in a hot tureen.
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 + leektop 6% of all pairsSmell alikemoderateCooked together30 recipes
Shared aroma: 1-octen-3-ol (mushroom, earthy).
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Butter + milktop 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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Potato + milktop 9% of all pairsSmell alikemoderateCooked together3,611 recipes
Shared aroma: (e,z)-2,6-nonadienal (cucumber, melon).
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Leek + peppertop 12% of all pairsSmell alikemoderateCooked together965 recipes
Shared aroma: coumarin (sweet, hay).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Potatoes
- Break down when boiled and mashed, giving the soup its body and smooth texture.
- Leeks or onions
- Add aromatic flavour as they soften and sweeten during sweating and boiling.
- Butter
- Adds richness and carries flavour from the sweated vegetables into the soup.
- Milk
- Adds creaminess and mild sweetness, rounding out the soup's flavour.
- Tapioca
- Thickens the soup as its starch gelatinises during gentle boiling.
The step that matters
Sprinkling in the tapioca. Tapioca must be added slowly while stirring constantly so the starch disperses evenly; dumped in at once it clumps into lumps that do not dissolve. Gentle boiling then fully swells the starch and thickens the soup.
Swap the leek
How well each one fits the dish's main ingredients (potato, butter, pepper, milk):
- Capsicumfits better
- Asparagusfits better
- Tomatofits better
- Leekthe original
Fit is the average pairing score against potato, butter, pepper, milk. 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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