Why it works: Rhubarb and lemon match in chemistry and in kitchens. They rank in the top 7% of all ingredient pairs, and cooks put them together in 546 recipes. Both carry acetic acid, which smells sour, vinegar. The science ↓
Rhubarb Tart
Ingredients
Directions
The book gives no oven temperature. The 400°F (200°C) in the steps was added when the recipe was transcribed, as a starting point.
Prepare
Preheat the oven to 400°F (200°C).
Roll out the puff pastry and line the edges of a deep pie dish with it.
Wash, wipe, and cut the rhubarb into 1‑inch pieces. If the rhubarb is tough, remove the outer skin.
Assemble and bake
Pile the rhubarb in the dish, as it will shrink during cooking.
Sprinkle the sugar over the rhubarb.
Add a small amount of lemon juice and minced lemon peel for extra flavor, if desired.
Cover with the remaining pastry, decorate the edges, and bake for 30 to 45 minutes.
Glaze and finish
Brush the tart with beaten egg white.
Sprinkle with sifted sugar.
Return to the oven to set the glaze.
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 + lemontop 7% of all pairsSmell alikestrongCooked together546 recipes
Shared aroma: acetic acid (sour, vinegar).
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Sugar + lemontop 18% of all pairsSmell alikelowCooked together53,532 recipes
Shared aroma: 2-nonenal (fatty, green).
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Rhubarb + sugartop 18% of all pairsSmell alikemoderateCooked together1,852 recipes
Shared aroma: 1-penten-3-one (fish, pungent).
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Egg + lemontop 19% of all pairsSmell alikelowCooked together44,316 recipes
Shared aroma: (e,e)-2,4-decadienal (fatty, deep fried).
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Sugar + eggtop 21% of all pairsSmell alikemoderateCooked together122,807 recipes
Shared aroma: 2-nonenal (fatty, green).
Sugar and lemon barely smell alike, yet cooks put them together in 53,532 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
- Puff pastry
- Forms the flaky, layered crust that encloses the filling and browns in the oven.
- Rhubarb
- Provides the tart filling and its sharp acidity, which balances the sugar.
- Moist sugar
- Sweetens the rhubarb and draws out its juices, forming a syrup in the tart.
- Egg white
- Brushed on top, it sets into a glossy, lightly browned glaze.
The step that matters
Piling the rhubarb in the dish. Rhubarb shrinks and releases juice as it cooks. Piling it high lets the filling settle without leaving gaps or a soggy, sunken top under the pastry.
Swap the lemon
The recipe marks lemon as optional. How well each one fits the dish's main ingredients (rhubarb, sugar, egg):
- Vanillafits better
- Raisinfits about as well
- Lemonthe original
- Figfits about as well
Fit is the average pairing score against rhubarb, sugar, egg. 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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