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 ↓
Soda Water
Ingredients
Directions
Make the syrup and acid solution
Dissolve 1 ½ pounds of white sugar in 1 quart of hot water.
Dissolve 1 ⅓ oz of citric acid in ½ teacup of hot water.
When cool, mix the sugar and citric acid solutions together.
Finish and foam
Beat the white of 1 egg and stir it into the mixture.
Flavor with lemon or your choice of flavor.
Add bicarbonate of soda to make it foam.
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
- White sugar
- Provides sweetness and body to the drink.
- Citric acid
- Adds sharp acidity and reacts with bicarbonate of soda to release gas.
- Egg white
- Its proteins trap air and help create a light foam.
- Bicarbonate of soda
- Reacts with the acid to release carbon dioxide, making the drink fizz and foam.
The step that matters
Add bicarbonate of soda to make it foam. Bicarbonate of soda and citric acid react to release carbon dioxide gas. Adding it too early, while the mixture is still warm or before the solutions are combined, lets the gas escape before the drink is ready. Adding it at the end keeps the fizz.
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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