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 cornstarch and sugar in a saucepan.
Add boiling water and stir and cook until there is no taste of raw starch.
Beat egg yolks.
Add a little of the cornstarch mixture to the yolks, then combine with the hot mixture.
Cook over low heat until the mixture thickens.
Remove from heat.
Add butter, lemon juice, and lemon rind.
Cool slightly.
Pour into a baked pie shell.
Top and bake
Beat egg whites until stiff.
Gradually add sugar.
Spread meringue over the pie.
Bake at 275°F (135°C) until lightly browned.
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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Butter + lemontop 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
- Cornstarch
- Thickens the filling as it cooks with the hot liquid, giving it a sliceable body.
- Egg yolks
- Enrich and thicken the filling, adding richness and a smooth, custard-like texture.
- Lemon juice
- Adds the sharp acidity that balances the sweetness of the filling.
- Sugar
- Sweetens the filling and, in the meringue, stabilizes the whipped egg whites.
- Egg whites
- Whipped into foam, they form the light meringue topping that sets and browns in the oven.
- Butter
- Adds richness and a smooth mouthfeel to the finished filling.
The step that matters
Cooking the filling until the starch is fully cooked. Starch only thickens properly once it is heated past its gelatinization point and cooked through. Stopping early leaves a raw, starchy taste and a filling that stays runny or cloudy.
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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