Why it works: Flour and sugar are a kitchen classic. They rank in the top 15% of all ingredient pairs, and cooks put them together in 92,116 recipes. Both carry phenylacetaldehyde, which smells hawthorne, honey. The science ↓
Lemon Pie
Ingredients
Directions
Make the filling
Grate the lemon rind and squeeze the juice.
In a saucepan, combine lemon juice, grated rind, flour, sugar, water, and egg yolks.
Boil the mixture until it thickens.
Assemble and bake
Bake a pie crust until light brown.
Spread the thickened lemon filling into the baked pie crust.
Beat the egg whites until frothy, adding sugar to taste.
Spread the beaten egg whites over the pie and brown 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 + 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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Lemon + flourtop 17% of all pairsSmell alikemoderateCooked together30,404 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Lemon + sugartop 18% of all pairsSmell alikelowCooked together53,532 recipes
Shared aroma: 2-nonenal (fatty, green).
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Lemon + eggtop 19% of all pairsSmell alikelowCooked together44,316 recipes
Shared aroma: (e,e)-2,4-decadienal (fatty, deep fried).
Flour and egg barely smell alike, yet cooks put them together in 106,462 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
- Egg yolks
- Thicken the filling as they set with heat, giving it a rich, smooth body.
- Flour
- Stabilizes the filling by thickening the liquid so it holds its shape when cut.
- Egg whites
- Whipped into a foam that forms the light topping, which browns in the oven.
- Lemon
- Provides the tart lemon flavor and acidity that balances the sugar.
The step that matters
Boil the mixture until it thickens. Flour starch thickens only when it reaches a boil and is stirred, and egg yolks must be heated enough to set. Underheating leaves a runny filling, while overheating can make the yolks curdle.
Swap the lemon
How well each one fits the dish's main ingredients (flour, sugar, egg):
- Raisinfits better
- Vanillafits better
- Lemonthe original
- Figfits about as well
Fit is the average pairing score against flour, sugar, 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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