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 ↓
To Make Icing for Cakes
Ingredients
Directions
In a saucepan, moisten the powdered sugar and bring it to a boil.
In a separate bowl, whip the egg whites until stiff peaks form.
Stir the whipped egg whites and lemon juice into the boiled sugar.
Continue mixing until the icing is thick enough to fall in a thread from the spoon.
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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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
- Powdered sugar
- Provides sweetness and the bulk that gives the icing its body.
- Egg whites
- Whipped into a foam, they add lightness and help the icing set with an airy texture.
- Lemon juice
- Adds acidity that stabilizes the whipped egg white foam and balances the sweetness.
The step that matters
Mixing until the icing forms a thread. Mixing stops too early and the icing stays runny and won't hold on a cake. Mixing too long can make it stiff and dull. The thread test shows when the sugar and foam have combined to the right thickness.
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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