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
Prepare the filling
Bake your pie crust.
In a bowl, mix sugar and flour.
Pour in boiling water and stir until combined.
Add grated lemon and butter, then heat on the stove until thick.
Stir in beaten egg yolks.
Assemble and brown
Pour filling into the crust and spread beaten egg whites on top.
Brown lightly in the oven.
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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Sugar + flourtop 15% of all pairsSmell alikemoderateCooked together92,116 recipes
Shared aroma: phenylacetaldehyde (hawthorne, honey).
-
Flour + eggtop 15% of all pairsSmell alikelowCooked together106,462 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Lemon + buttertop 16% of all pairsSmell alikemoderateCooked together41,227 recipes
Shared aroma: 3-hexenal (apple, fruity).
-
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
- Sugar
- Sweetens the filling and balances the sharpness of the lemon.
- Flour
- Thickens the filling so it sets into a sliceable custard.
- Eggs
- Yolks thicken the filling, and whites form a light topping that browns in the oven.
- Grated lemon
- Adds acidity and lemon aroma to the filling.
- Butter
- Adds richness and a smooth texture to the filling.
The step that matters
Heat the filling until thick before adding the egg yolks. Starch from the flour must be cooked to thicken the filling. Adding yolks to a very hot mixture while stirring vigorously helps prevent scrambling, so the filling stays smooth and glossy.
Swap the lemon
How well each one fits the dish's main ingredients (sugar, flour, butter, egg):
- Raisinfits better
- Vanillafits better
- Figfits about as well
- Lemonthe original
Fit is the average pairing score against sugar, flour, butter, egg. 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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