Why it works: Flour and butter are a kitchen classic. They rank in the top 12% of all ingredient pairs, and cooks put them together in 124,287 recipes. Both carry isobutyraldehyde, which smells malty, green. The science ↓
Lemon Jelly Filling
Ingredients
Directions
Prepare the filling
Grate the yellow rind from the lemons and squeeze out the juice.
In a bowl, mix the sugar and egg yolks, then add the beaten egg whites and lemon juice.
Pour in the boiling water and stir in the flour mixed with the water until smooth.
Add the melted butter and cook until thickened.
Finish and serve
Once cooled, spread between layers of cake.
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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Flour + buttertop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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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).
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Lemon + buttertop 16% of all pairsSmell alikemoderateCooked together41,227 recipes
Shared aroma: 3-hexenal (apple, fruity).
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Lemon + flourtop 17% of all pairsSmell alikemoderateCooked together30,404 recipes
Shared aroma: isobutyraldehyde (malty, green).
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
- Eggs
- Yolks and whites thicken and enrich the filling as it cooks, giving it body and a creamy texture.
- Sugar
- Sweetens the filling and helps give it a smooth, glossy set.
- Lemons
- Juice supplies sharp acidity and the rind adds bright lemon aroma.
- Flour
- Starch thickens the liquid as it heats, helping the filling set firm.
- Butter
- Adds richness and a silky mouthfeel to the cooked filling.
The step that matters
Cook until thickened. Egg proteins and starch must be heated enough to thicken the filling, but overheating can curdle the eggs and leave lumps, so cook gently and stir constantly.
Swap the lemon
How well each one fits the dish's main ingredients (sugar, egg, flour, butter):
- Raisinfits better
- Vanillafits better
- Figfits about as well
- Lemonthe original
Fit is the average pairing score against 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.
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