Why it works: Lemon and walnut 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
Make the lemon filling
Heat the water in a double boiler.
Add half of the sugar to the water.
Beat the egg yolks with the remaining sugar in a separate bowl.
Add the butter, lemon juice, and rind to the egg mixture.
Stir in the flour.
Pour the mixture into the boiling water.
Stir the mixture constantly for 15 minutes.
Bake and top the pie
Bake a pie crust until golden brown.
Let the crust cool.
Pour the lemon filling into the cooled crust.
Beat the egg whites until stiff.
Spread the stiff egg whites over the top of the pie.
Sprinkle 2 tablespoons of sugar over the egg whites.
Place the pie in the oven to brown.
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.
-
Lemon + walnuttop 10% of all pairsSmell alikestrongCooked together2,149 recipes
Shared aroma: 2-nonenal (fatty, green).
-
Flour + buttertop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Flour + walnuttop 12% of all pairsSmell alikemoderateCooked together5,873 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Sugar + flourtop 15% of all pairsSmell alikemoderateCooked together92,116 recipes
Shared aroma: phenylacetaldehyde (hawthorne, honey).
-
Butter + walnuttop 15% of all pairsSmell alikemoderateCooked together6,832 recipes
Shared aroma: eucalyptol (eucalyptus, herbal).
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
- Egg yolks
- Thicken the filling as they cook and add richness to the custard.
- Flour
- Thickens the filling so it sets into a sliceable custard.
- Sugar
- Sweetens the filling and balances the sharpness of the lemon.
- Lemon juice and rind
- Provide the sharp, aromatic citrus flavor that defines the filling.
- Egg whites
- Whip into a stiff meringue that forms the browned topping.
- Butter
- Adds fat for a smoother, richer texture in the filling.
The step that matters
Stir the filling constantly for 15 minutes. Egg yolks and flour can lump or scorch on contact with hot liquid if left unstirred. Constant stirring keeps the custard smooth and lets the starch thicken evenly as the yolks cook.
Swap the walnut
How well each one fits the dish's main ingredients (lemon, sugar, egg, flour, butter):
- Almondfits better
- Pistachiofits better
- Milletfits better
- Walnutthe original
Fit is the average pairing score against lemon, sugar, egg, 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.
More lemon pie recipes
You might also like
Lemon Cake228 recipes
Lemon Ice147 recipes
Lemon Sherbet103 recipes
Lemon Custard64 recipesThe free Flavor Lab newsletter: one surprising pairing a week and the molecular reason it works, in 60 seconds. No spam, unsubscribe anytime.
Prefer an account? Create a free account to save pairings and unlock the full chemistry.