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 300°F (150°C) in the steps was added when the recipe was transcribed, as a starting point.
Make the filling
Combine sugar, boiling water, and butter in a saucepan.
Cook until melted.
Thicken the mixture with cornstarch.
Let it cool.
Mix in the egg yolks and the zest of 1½ lemons.
Bake and top
Pour the mixture into a rich pie crust.
Bake at 300°F (150°C) until set.
Whip the egg whites to make a meringue.
Spread the meringue on top of the pie.
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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Butter + eggtop 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 filling as it heats, giving it a set, sliceable body.
- Egg yolks
- Enrich and thicken the filling, adding richness and a smooth custard texture.
- Egg whites
- Whipped into a meringue that forms the topping, adding airy structure and light browning.
- Butter
- Adds fat for richness and a smooth, velvety mouthfeel to the filling.
- Lemons
- Zest supplies aromatic citrus flavour that gives the pie its tang.
The step that matters
Thicken the mixture with cornstarch. Cornstarch only thickens fully when the mixture is heated enough for the starch granules to swell and gel. Undercooked filling stays runny and will not set properly when baked and cooled.
Swap the walnut
How well each one fits the dish's main ingredients (sugar, butter, egg, lemon):
- Almondfits better
- Pistachiofits about as well
- Walnutthe original
- Milletfits about as well
Fit is the average pairing score against sugar, butter, egg, 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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