Why it works: Walnut and lemon match in chemistry and in kitchens. They rank in the top 10% of all ingredient pairs, and cooks put them together in 2,149 recipes. Both carry 2-nonenal, which smells fatty, green. The science ↓
Lemon Pie
Ingredients
Directions
The book gives no oven temperature. The 400°F (200°C) in the steps was added when the recipe was transcribed, as a starting point.
Prepare the crust
Preheat oven to 400°F (200°C).
Line a pie tin with flaky crust, prick it with a fork, and bake until golden.
Make the filling
In a saucepan, combine boiling water, sugar, and butter; bring to a boil.
Mix cornstarch with cold water, then add to the boiling mixture.
Beat the egg yolks and add them along with the lemon juice and a little lemon rind.
Cook until thickened, then pour the filling into the baked crust.
Top and bake
Beat the egg whites until soft peaks form, then gradually add 2 tablespoons of sugar and a little lemon juice.
Spread the meringue over the filling and bake until lightly 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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Walnut + lemontop 10% of all pairsSmell alikestrongCooked together2,149 recipes
Shared aroma: 2-nonenal (fatty, green).
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Butter + walnuttop 15% of all pairsSmell alikemoderateCooked together6,832 recipes
Shared aroma: eucalyptol (eucalyptus, herbal).
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Butter + lemontop 16% of all pairsSmell alikemoderateCooked together41,227 recipes
Shared aroma: 3-hexenal (apple, fruity).
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Egg + buttertop 17% of all pairsSmell alikemoderateCooked together118,967 recipes
Shared aroma: decanal (soap, orange peel).
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Sugar + buttertop 17% of all pairsSmell alikemoderateCooked together98,233 recipes
Shared aroma: guaiacol (smoky, sweet).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Cornstarch
- Thickens the lemon filling as it cooks and boils.
- Eggs
- Egg yolks thicken the filling; whites whip into the meringue topping.
- Sugar
- Sweetens the filling and helps stabilise the whipped egg whites.
- Lemon
- Provides acidity and aroma that balance the sweetness of the filling.
- Butter
- Adds richness and a smooth texture to the filling.
The step that matters
Cook the filling until thickened. Cornstarch only thickens fully when the mixture reaches a boil and is cooked through. Stopping early leaves a runny filling, which will not set when cooled.
Swap the walnut
How well each one fits the dish's main ingredients (sugar, egg, butter, lemon):
- Almondfits better
- Pistachiofits about as well
- Walnutthe original
- Milletfits about as well
Fit is the average pairing score against sugar, egg, butter, lemon. 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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