Name: Kidney Bean Salad
Ingredients: 1 can red kidney beans; 1 large onion, chopped fine; 1 tablespoon flour; 1 tablespoon butter; 2 hard-boiled eggs; 4 tablespoons vinegar; 2-3 tablespoons sour relish; 1 teaspoon salt; Dash of cayenne pepper

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 ↓

Kidney Bean Salad

Ingredients

Directions

Prepare the dressing

Heat the beans.
Melt the butter in a pan and stir in the flour; cook until well blended.
Add vinegar and the juice from the beans; cook until thick, stirring to avoid lumps.
Add the chopped onion, salt, and cayenne pepper; let cool.

Assemble and serve

Toss in the beans and chopped hard-boiled eggs before serving.

Recipe from a historical cookbook (Internet Archive).

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.

Onion + peppertop 11% of all pairs

Smell alikemoderate

Cooked together68,474 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Flour + buttertop 12% of all pairs

Smell alikelow

Cooked together124,287 recipes

Shared aroma: isobutyraldehyde (malty, green).
Onion + vinegartop 14% of all pairs

Smell alikemoderate

Cooked together18,226 recipes

Shared aroma: acetic acid (sour, vinegar).
Vinegar + peppertop 14% of all pairs

Smell alikemoderate

Cooked together27,814 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Kidney beans + oniontop 15% of all pairs

Smell alikemoderate

Cooked together1,050 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

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

Flour: Thickens the vinegar and bean juice into a smooth, cohesive dressing.
Butter: Carries the flour and adds richness to the base of the dressing.
Vinegar: Adds acidity that sharpens the flavour and balances the sweetness of the beans.
Red kidney beans: Provide the main body, texture and protein of the salad.
Hard-boiled eggs: Add soft, creamy texture and mild richness to the salad.

The step that matters

Cook the flour and butter until well blended, then add the vinegar and stir constantly. Cooking flour in fat before adding liquid lets the starch disperse evenly. Stirring while the mixture thickens prevents lumps from forming as the starch swells and sets.

Swap the kidney beans

How well each one fits the dish's main ingredients (onion, flour, butter, egg, vinegar, pepper):

Sesamefits better
Black-eyed peafits better
Almondfits better
Kidney beansthe original

Fit is the average pairing score against onion, flour, butter, egg, vinegar, 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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Kidney Bean Salad