Why it works: Butter and flour 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.
Make the custard
Beat the eggs with sugar, butter, flour, and water until well combined.
Add the lemon juice to the mixture.
Cook the mixture until thick.
Pour the thickened mixture into a baked pastry shell.
Make the meringue and bake
Beat the egg whites until stiff.
Gradually add sugar to the beaten egg whites.
Spread the meringue over the custard.
Bake the pie in a 350°F (175°C) oven until the meringue is 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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Butter + flourtop 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).
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Egg + flourtop 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).
Butter and flour 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
- Thicken the custard as they cook and add richness to the filling.
- Lemon juice
- Adds acidity and bright lemon flavour that balances the sweetness.
- Sugar
- Sweetens the custard and meringue and helps the egg whites hold their structure.
- Egg whites
- Whipped into a foam that forms the light, browned meringue topping.
- Flour
- Helps thicken the custard so it sets firm rather than runny.
The step that matters
Cook the custard until thick. Egg proteins set as they heat, so the filling thickens only when cooked enough. Stop too early and the pie stays runny; overcooking can curdle the eggs.
Swap the lemon
How well each one fits the dish's main ingredients (egg, sugar, butter, flour):
- Raisinfits better
- Vanillafits better
- Figfits about as well
- Lemonthe original
Fit is the average pairing score against egg, sugar, butter, flour. 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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