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 ↓
Rhubarb Pie
Ingredients
Directions
Prepare the filling
Pour boiling water over the chopped rhubarb and let it sit for 4-5 minutes, then drain the water.
In a bowl, mix the drained rhubarb with sugar, egg yolks, butter, and flour.
Moisten the mixture with water and pour it into the lower pie crust.
Make the meringue and finish
Beat the egg whites until stiff, then gradually add sugar to make a meringue.
Spread the meringue over the top of the pie and return it to 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.
Photo for illustrative purposes only · Contact us to use it
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.
-
Rhubarb + flourtop 7% of all pairsSmell alikestrongCooked together670 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
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).
-
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
- Rhubarb
- Provides the tart flavour and the bulk of the pie's filling.
- Sugar
- Sweetens the filling and balances the sharp taste of the rhubarb.
- Egg yolks
- Thicken the filling as they set and add richness.
- Flour
- Thickens the filling so it holds its shape when sliced.
- Egg whites
- Whipped into a meringue that gives a light, airy topping that browns in the oven.
The step that matters
Draining the rhubarb after scalding. Rhubarb releases a lot of liquid as it cooks. Draining it after the brief soak keeps the filling from becoming watery, so it sets properly under the crust and meringue.
Swap the rhubarb
How well each one fits the dish's main ingredients (sugar, egg, butter, flour):
- Cinnamonfits better
- Nutmegfits better
- Jalapenofits better
- Rhubarbthe original
Fit is the average pairing score against sugar, egg, butter, 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.
More rhubarb pie recipes
You might also like
The 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.

Rhubarb Marmalade35 recipes
Rhubarb Jelly28 recipes
White Cake431 recipes
Pound Cake373 recipes