Why it works: Lemon and sugar are a kitchen classic. They rank in the top 18% of all ingredient pairs, and cooks put them together in 53,532 recipes. Both carry 2-nonenal, which smells fatty, green. The science ↓
Lemon Custards
Ingredients
Directions
Make the custard
Beat the yolks of 18 eggs until they are as white as cream.
Grate the peel of 1 lemon and add the juice of 2 lemons.
Sweeten the mixture to taste.
Pour 1 pint of boiling water into the lemon and sugar mixture.
Add the egg yolks and stir everything together.
Strain the mixture through a sieve into an earthen pitcher.
Thicken and serve
Place the pitcher in a kettle of boiling water and stir until it thickens.
Pour the custard into jelly glasses.
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.
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Lemon + sugartop 18% of all pairsSmell alikelowCooked together53,532 recipes
Shared aroma: 2-nonenal (fatty, green).
-
Egg + lemontop 19% of all pairsSmell alikelowCooked together44,316 recipes
Shared aroma: (e,e)-2,4-decadienal (fatty, deep fried).
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Egg + sugartop 21% of all pairsSmell alikemoderateCooked together122,807 recipes
Shared aroma: 2-nonenal (fatty, green).
Lemon and sugar 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
- Egg yolks
- Thicken the custard as they set with gentle heat, giving it a rich, smooth body.
- Lemon juice
- Adds acidity that brightens the sweetness and balances the richness of the yolks.
- Sugar
- Sweetens the custard and balances the sharpness of the lemon.
- Lemon zest
- Adds fragrant lemon aroma from the peel's aromatic oils.
The step that matters
Thickening over boiling water. Egg yolks thicken only within a narrow temperature range. Stirring over the heat gently and watching for it to thicken keeps the custard smooth, since overheating can cause the yolks to scramble and curdle.
Swap the lemon
How well each one fits the dish's main ingredients (egg, sugar):
- Vanillafits better
- Raisinfits about as well
- Lemonthe original
- Datesfits less well
Fit is the average pairing score against egg, 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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