Why it works: Rhubarb and flour match in chemistry and in kitchens. They rank in the top 7% of all ingredient pairs, and cooks put them together in 670 recipes. Both carry isobutyraldehyde, which smells malty, green. The science ↓
Lemon Rhubarb Pie
Ingredients
Directions
The book gives no oven temperature. The 350°F (175°C) in the steps was added when the recipe was transcribed, as a starting point.
Make the filling
In a double boiler, combine stewed rhubarb, egg yolks, butter, sugar, and flour.
Cook until thick like custard.
Pour the mixture into a baked pie crust.
Top and bake
Beat the egg whites until stiff, then sweeten and spread over the filling.
Bake in a 350°F (175°C) oven until the meringue is 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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Rhubarb + flourtop 7% of all pairsSmell alikestrongCooked together670 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Sugar + flourtop 15% of all pairsSmell alikemoderateCooked together92,116 recipes
Shared aroma: phenylacetaldehyde (hawthorne, honey).
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Egg + flourtop 15% of all pairsSmell alikelowCooked together106,462 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Egg + buttertop 17% of all pairsSmell alikemoderateCooked together118,967 recipes
Shared aroma: decanal (soap, orange peel).
Butter and flour 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
- Stewed rhubarb
- Provides the tart fruit flavor and the bulk of the filling.
- Egg yolks
- Thicken the filling into a custard as they cook.
- Sugar
- Sweetens the filling and helps the meringue brown.
- Egg whites
- Whipped into a stiff foam that forms the browned meringue topping.
- Butter
- Adds richness and smoothness to the custard filling.
- Flour
- Helps stabilize the custard so it sets thick rather than runny.
The step that matters
Cooking the custard until thick. Egg yolks thicken only when heated gently and long enough to set, but overheating can curdle them. Cook in a double boiler and stop once the mixture coats a spoon like custard, so the filling sets smoothly.
Swap the rhubarb
How well each one fits the dish's main ingredients (egg, butter, sugar, flour):
- Cinnamonfits better
- Nutmegfits better
- Jalapenofits better
- Rhubarbthe original
Fit is the average pairing score against egg, butter, sugar, flour. 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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