Why it works: Flour and butter are a kitchen classic. They rank in the top 12% of all ingredient pairs, and cooks put them together in 124,287 recipes. Both carry isobutyraldehyde, which smells malty, green. The science ↓
Lemon Pie
Ingredients
Directions
Make the filling
Mix the flour and sugar together.
Slowly add the boiling water and cook for 20 minutes, stirring frequently.
Add the mixture to the beaten egg yolk, then add butter and lemon juice, and cook until the egg thickens.
Assemble and bake
When the mixture is cool, place it in a baked pie crust.
Cover with meringue made from the beaten egg white and powdered sugar, then bake until light brown.
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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Flour + buttertop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Flour + sugartop 15% of all pairsSmell alikemoderateCooked together92,116 recipes
Shared aroma: phenylacetaldehyde (hawthorne, honey).
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Flour + eggtop 15% of all pairsSmell alikelowCooked together106,462 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Lemon + buttertop 16% of all pairsSmell alikemoderateCooked together41,227 recipes
Shared aroma: 3-hexenal (apple, fruity).
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Flour + lemontop 17% of all pairsSmell alikemoderateCooked together30,404 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
- Flour
- Thickens the filling as it cooks with the sugar and liquid.
- Egg yolk
- Thickens the filling as it cooks and adds richness.
- Egg white
- Whips into the meringue topping that sets and browns in the oven.
- Lemon juice
- Adds tartness that balances the sweetness of the filling.
- Sugar
- Sweetens the filling and helps stabilize the meringue.
The step that matters
Cooking the filling until the egg thickens. Egg yolk thickens when heated, but if it gets too hot it can curdle or scramble. Cook gently and keep stirring so the filling becomes smooth and thick rather than lumpy.
Swap the lemon
How well each one fits the dish's main ingredients (flour, sugar, egg, butter):
- Raisinfits better
- Vanillafits better
- Figfits about as well
- Lemonthe original
Fit is the average pairing score against flour, sugar, egg, 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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