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 and sift cornstarch, flour, sugar, and salt.
Gradually add boiling water while stirring constantly.
Cook over hot water until the mixture thickens.
Remove from heat; add butter, slightly beaten egg yolks, grated lemon rind, and lemon juice.
Bake and top
Line a pie pan with pastry; brush with egg white.
Pour in the slightly cooled mixture and bake until the pastry is well browned.
Remove from oven, cool slightly, and spread with meringue.
Return to oven to bake and brown the meringue.
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.
-
Flour + buttertop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Sugar + flourtop 15% of all pairsSmell alikemoderateCooked together92,116 recipes
Shared aroma: phenylacetaldehyde (hawthorne, honey).
-
Egg + flourtop 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).
-
Lemon + flourtop 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 boiling water.
- Egg yolks
- Enrich the filling and help it set to a rich, smooth custard.
- Lemon juice
- Adds the sharp acidity that defines the pie's flavor.
- Sugar
- Sweetens the filling and balances the acidity of the lemon.
- Flour
- Adds body and helps thicken the filling alongside the cornstarch.
- Butter
- Adds richness and a smooth mouthfeel to the filling.
The step that matters
Cooking the filling until it thickens. Starch thickens only when heated in liquid, so the mixture must be cooked long enough for the cornstarch to swell fully. Stirring keeps it smooth and prevents lumps. Adding the egg yolks off the heat avoids scrambling them, and the filling should be cooled slightly before it goes into the pastry.
Swap the lemon
How well each one fits the dish's main ingredients (sugar, egg, flour, butter):
- Raisinfits better
- Vanillafits better
- Figfits about as well
- Lemonthe original
Fit is the average pairing score against sugar, egg, 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.
More lemon pie recipes
You might also like
Lemon Cake228 recipes
Lemon Ice147 recipes
Lemon Sherbet103 recipes
Lemon Custard64 recipesThe free Flavor Lab newsletter: one surprising pairing a week and the molecular reason it works, in 60 seconds. No spam, unsubscribe anytime.
Prefer an account? Create a free account to save pairings and unlock the full chemistry.