Why it works: Beans and onion match in chemistry and in kitchens. They rank in the top 7% of all ingredient pairs, and cooks put them together in 5,242 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Bean Soup
Ingredients
Directions
Prepare the beans
Soak the beans in cold water overnight.
Cook the beans slowly for 4 to 5 hours until tender.
Drain the beans through a colander.
Make the soup
In a bowl, rub together the butter, flour, and salt.
Pour a little of the hot bean liquid over the mixture and stir it into the remaining bean liquid.
Add seasoning and enough water to make 1 quart.
Cook for an additional 10 minutes.
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 + oniontop 7% of all pairsSmell alikestrongCooked together5,242 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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Flour + buttertop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Butter + oniontop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
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Flour + oniontop 17% of all pairsSmell alikemoderateCooked together32,460 recipes
Shared aroma: isobutyraldehyde (malty, green).
Flour and butter 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
- White beans
- Provide the main body and starchy texture of the soup once cooked until tender.
- Butter
- Adds richness and fat, carrying flavour and giving the soup a smoother mouthfeel.
- Flour
- Mixed with butter and hot bean liquid to thicken the soup and give it body.
The step that matters
Pour the hot liquid into the butter and flour mixture slowly. Stirring a little hot liquid into the butter and flour paste first helps it blend smoothly. Adding it all at once can leave lumps of flour that do not dissolve into the soup.
Swap the onion
How well each one fits the dish's main ingredients (beans, flour, butter):
- Sweet potatofits better
- Chivefits better
- Shallotfits better
- Onionthe original
Fit is the average pairing score against beans, flour, butter. 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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