Why it works: Sugar and lemon 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 ↓
Clear Icing
Ingredients
Directions
The book says “a cool oven”. The 300°F in the steps is the modern equivalent, not the book's own figure.
Make the icing
In a bowl, mix together the sugar, lemon juice, and egg whites until smooth.
Finish and set
Pour the mixture over the cakes.
If the icing is not drying, place it in a cool oven (300°F / 150°C) to set.
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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Sugar + lemontop 18% of all pairsSmell alikelowCooked together53,532 recipes
Shared aroma: 2-nonenal (fatty, green).
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Lemon + eggtop 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
- Sugar
- Provides sweetness and, dissolved into the egg whites, forms the body of the glossy icing.
- Egg whites
- Provide the structure that sets the icing into a smooth, glossy, clear coating.
- Lemon juice
- Adds acidity that balances sweetness and helps stabilise the egg white foam.
The step that matters
Drying the icing in the oven. Egg white and sugar icings set through gentle heat and moisture loss, so an oven that is too hot can cook the whites into a cloudy, tacky surface. Only use the cool oven if the icing is not drying on its own.
Swap the lemon
How well each one fits the dish's main ingredients (sugar, egg):
- Vanillafits better
- Raisinfits about as well
- Lemonthe original
- Datesfits less well
Fit is the average pairing score against 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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