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
The book gives no oven temperature. The 350°F (175°C) in the steps was added when the recipe was transcribed, as a starting point. The book gives no cooking times either; the times in the steps were added in transcription, so check for doneness rather than trusting the clock.
Prepare
Preheat the oven to 350°F (175°C).
In a bowl, mix the sugar, lemon juice, flour, and butter.
Add the hot water and stir until combined.
Separate the egg whites and set aside for icing.
Bake and serve
Pour the mixture into a pre-baked pie crust.
Bake until set, about 25-30 minutes.
Whip the egg whites and spread over the pie as icing before serving.
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).
-
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
- Eggs
- Whipped whites form a foam that gives the topping its light, stable structure.
- Sugar
- Provides sweetness and helps the whipped egg white topping hold its foam.
- Lemon juice
- Adds acidity that brightens the filling and balances the sweetness.
- Flour
- Thickens the filling as it heats, giving it body rather than a runny texture.
- Butter
- Adds fat that enriches the filling and softens its texture.
The step that matters
Bake until just set. The egg in the filling sets as its proteins firm with heat. Overbaking squeezes out liquid and can make the filling curdle or weep, so check for a set centre rather than baking for a fixed time alone.
Swap the lemon
How well each one fits the dish's main ingredients (egg, sugar, flour, butter):
- Raisinfits better
- Vanillafits better
- Figfits about as well
- Lemonthe original
Fit is the average pairing score against egg, sugar, 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.
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