Why it works: Beans and pepper are a kitchen classic. They rank in the top 11% of all ingredient pairs, and cooks put them together in 4,733 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
String- Bean Soup
Ingredients
Directions
Prepare the beans
Remove the strings from the beans.
Cut the beans into small pieces.
Wash the beans in cold water.
Boil the beans in salted boiling water until tender.
Rub the beans through a sieve using a potato masher.
Make the soup
In a clean saucepan, melt the butter and flour over medium heat, stirring until smooth.
Gradually stir in the boiling water.
Bring the mixture to a boil.
Add the prepared beans to the soup.
Season the soup with salt, white pepper, and cayenne.
Let the soup boil once, then serve.
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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Beans + peppertop 11% of all pairsSmell alikemoderateCooked together4,733 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Beans + flourtop 11% of all pairsSmell alikemoderateCooked together2,080 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Beans + buttertop 19% of all pairsSmell alikemoderateCooked together2,799 recipes
Shared aroma: trans-2-nonenal (cardboard, fatty).
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White pepper + peppertop 19% of all pairsSmell alikelowCooked together1,478 recipes
Shared aroma: piperonal (bitter, coconut).
Butter and flour barely smell alike, yet cooks put them together in 124,287 recipes: they work on texture and structure more than aroma.
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Beans
- Form the main body of the soup, and their pulp gives it substance and texture.
- Butter
- Carries flavour and enriches the soup as it melts with the flour.
- Flour
- Thickens the soup as its starch swells when cooked in the melted butter and liquid.
The step that matters
Blend the flour and butter with the water gradually. Flour thickens by starch swelling in hot liquid. If the water goes in all at once or is not stirred well, the flour clumps and the soup turns lumpy instead of smooth.
Swap the white pepper
How well each one fits the dish's main ingredients (beans, butter, flour, pepper):
- Turmericfits better
- Parsleyfits better
- Sagefits better
- White pepperthe original
Fit is the average pairing score against beans, butter, flour, 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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