Why it works: Lemon and pepper match in chemistry and in kitchens. They rank in the top 3% of all ingredient pairs, and cooks put them together in 27,047 recipes. Both carry trans-2-nonenal, which smells cardboard, fatty. The science ↓
Leek Soup
Ingredients
Directions
Prepare
Cut off the coarse part of the green ends of the leeks and cut the leeks lengthways to brush out the grit.
Wash the leeks well, ensuring no grit remains, then cut them into short pieces.
Peel, wash, and cut up the potatoes.
Make the soup
Cook both vegetables with 2 pints of water.
When the vegetables are quite tender, rub them through a sieve.
Return the mixture to the saucepan, add the butter, milk, and seasoning, and boil the soup up again.
Finish and serve
Before serving, add the lemon juice.
Serve with slices of toast or Allinson rusks.
Nutrition, whole recipe (rough)
Counts 5 of 6 ingredients. The other 1 aren't in our nutrition table and add nothing above, so the real totals are higher.
What these numbers assume: 5 portions
| Ingredient | Portion assumed | kcal |
|---|---|---|
| Milk | 1 cup (244ml) whole | 149 |
| Onion | 1 medium (110g) | 44 |
| Lemon | juice of 1 lemon (48ml) | 12 |
| Black Pepper | 1 tsp ground (2.3g) | 6 |
| Salt | 1 tsp (6g) | 0 |
| Water | not in our table | 0 |
One typical portion per ingredient; the recipe's quantities are not counted. A rough guide only, not for medical or dietary planning.
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. See the original page.
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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Lemon + peppertop 3% of all pairsSmell alikestrongCooked together27,047 recipes
Shared aroma: trans-2-nonenal (cardboard, fatty).
-
Leek + lemontop 8% of all pairsSmell alikestrongCooked together162 recipes
Shared aroma: 1-octen-3-ol (mushroom, earthy).
-
Leek + peppertop 12% of all pairsSmell alikemoderateCooked together965 recipes
Shared aroma: coumarin (sweet, hay).
-
Milk + lemontop 15% of all pairsSmell alikemoderateCooked together19,053 recipes
Shared aroma: 2-nonenal (fatty, green).
-
Leek + milktop 19% of all pairsSmell alikemoderateCooked together200 recipes
Shared aroma: ethyl butyrate (apple, fruity).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Leeks
- Form the main body and mild onion-like flavour of the soup.
- Potatoes (in the method)
- Starch thickens the soup and gives it a smooth, full texture once puréed.
- Milk
- Adds creaminess and softens the flavour of the soup.
- Lemon juice
- Adds acidity that brightens the flavour of the finished soup.
The step that matters
Wash the leeks thoroughly. Grit hides between the leek layers and cooking does not remove it. Slitting the leeks lengthways and rinsing each layer clears it out, so the sieved soup stays smooth and gritty-free.
Swap the leek
How well each one fits the dish's main ingredients (milk, lemon, pepper):
- Capsicumfits better
- Spinachfits better
- Asparagusfits better
- Leekthe original
Fit is the average pairing score against milk, lemon, 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.
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