Why it works: Butter and flour 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 ↓
Modern Cookery
Ingredients
Directions
The book says “a moderate oven”. The 350°F (175°C) in the steps is the modern equivalent, not the book's own figure.
Prepare
Preheat the oven to 350°F (175°C).
Make the custard
In a bowl, mix the hot ingredients with the butter, lemon rind, and lemon juice.
Gradually stir in the beaten egg yolks and flour (or crushed biscuits/macaroons).
Pour the mixture into a baking dish.
Bake and serve
Bake for 30 minutes or until firm in the middle.
Drizzle with clarified butter and sprinkle sugar on top before serving.
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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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Flour + sugartop 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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Butter + lemontop 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).
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
- Butter
- Adds richness and fat, giving the custard a smooth, soft texture.
- Eggs
- Egg yolks thicken and set the custard, giving it its firm, sliceable structure.
- Flour
- Thickens the mixture and gives it body so it holds together when baked.
- Lemon juice
- Adds acidity that brightens the flavour and balances the sweetness.
- Lemon rind
- Contributes aromatic citrus oils that give the custard its fragrance.
The step that matters
Stir in the beaten egg yolks gradually. Adding the yolks slowly and mixing well lets them blend evenly into the warm mixture, helping prevent lumps and curdling and keeping the custard smooth.
Swap the lemon
How well each one fits the dish's main ingredients (butter, egg, flour, sugar):
- Raisinfits better
- Vanillafits better
- Figfits about as well
- Lemonthe original
Fit is the average pairing score against butter, egg, flour, sugar. 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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