Name: Lemon Apple Pie
Ingredients: 2 cups chopped apples; 1 cup sugar; ½ cup water; 1 egg, well beaten; Juice and grated rind of 1 lemon; ½ cup rolled crackers; Plain pastry for pie crust

Why it works: Apple and lemon are a kitchen classic. They rank in the top 14% of all ingredient pairs, and cooks put them together in 7,551 recipes. Both carry trans-2-nonenal, which smells cardboard, fatty. The science ↓

Lemon Apple Pie

Oven, in the book's wordsA hot oven

Ingredients

Directions

The book says “a hot oven”. The 400°F (200°C) in the steps is the modern equivalent, not the book's own figure.

Prepare

Preheat the oven to 400°F (200°C).

Assemble and bake

Mix the chopped apples, sugar, water, beaten egg, lemon juice, lemon rind, and rolled crackers in a bowl.
Pour the mixture into a pie plate lined with plain pastry.
Cover with a top crust.
Bake in the preheated oven until golden brown.

Recipe from a historical cookbook (Internet Archive).

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.

Apple + lemontop 14% of all pairs

Smell alikemoderate

Cooked together7,551 recipes

Shared aroma: trans-2-nonenal (cardboard, fatty).
Apple + sugartop 18% of all pairs

Smell alikelow

Cooked together16,478 recipes

Shared aroma: beta-damascenone (apple, rose).
Sugar + lemontop 18% of all pairs

Smell alikelow

Cooked together53,532 recipes

Shared aroma: 2-nonenal (fatty, green).
Egg + lemontop 19% of all pairs

Smell alikelow

Cooked together44,316 recipes

Shared aroma: (e,e)-2,4-decadienal (fatty, deep fried).
Sugar + eggtop 21% of all pairs

Smell alikemoderate

Cooked together122,807 recipes

Shared aroma: 2-nonenal (fatty, green).

Apple and sugar barely smell alike, yet cooks put them together in 16,478 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

Apples: Provide the bulk and fruity flavor of the filling.
Sugar: Adds sweetness and helps draw moisture from the apples into a syrup.
Egg: Helps bind the filling so it sets rather than running when sliced.
Rolled crackers: Absorb excess juice from the apples so the filling stays thick.
Lemon: Adds acidity and brightness that balances the sweetness of the filling.