Why it works: Onion and pepper are a kitchen classic. They rank in the top 11% of all ingredient pairs, and cooks put them together in 68,474 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Lentil Soup
Ingredients
Directions
Prepare
Wash lentils in several waters until perfectly clean.
Soak lentils overnight in cold water.
Cook
Put lentils to the boil with 10 cupfuls water.
When the mixture boils, add cut vegetables and a pinch of baking soda.
Boil for 2 hours.
Strain and serve
Strain through a colander, rubbing lentils through, except the skins.
Return the strained lentils to the pot to warm, season with pepper and salt.
Serve very hot.
Nutrition, whole recipe (rough)
Counts 3 of 4 ingredients. The other 1 aren't in our nutrition table and add nothing above, so the real totals are higher.
What these numbers assume: 3 portions
| Ingredient | Portion assumed | kcal |
|---|---|---|
| Onion | 1 medium (110g) | 44 |
| 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.
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.
-
Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Lentils (in the method)
- Form the body of the soup as they soften and break down into a thick purée.
- Onions
- Add savoury sweetness and aroma as they cook down into the soup.
- Baking soda (in the method)
- Raises the pot's alkalinity, helping lentils soften faster during the long boil.
The step that matters
Rubbing the lentils through the colander. Pressing the cooked lentils through a sieve separates the soft pulp from the skins, which sets the smooth texture of the soup. Skipping or rushing this leaves the soup grainy.
“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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