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 ↓
Syrup-making
Ingredients
Directions
Prepare
Combine 2 pounds of granulated sugar and 1 pint of water in a pot and place it on the stove over high heat.
Prepare a bowl with 2-3 quarts of ice water.
Boil and test
When the mixture boils, dip your fingers into the ice water and quickly run them around the inside of the pot, avoiding the syrup, repeating 2-3 times.
Add 5-6 drops of lemon juice to the boiling sugar.
Dip the end of a thin stick in ice water, then into the boiling sugar, remove it, and dip it back into the ice water.
Check if the sugar on the stick is hard; if not, let it boil longer and repeat the test.
Test doneness by biting the sugar on the stick; it should crack easily without sticking to your teeth.
Finish
Once done, remove the pot from heat and set it in the ice water, ensuring the water surrounds the pot to prevent browning.
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).
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
- Granulated sugar
- Dissolves in water to form the syrup and sets firm as it boils, giving the candy-like test result.
- Water
- Dissolves the sugar so it can boil evenly into a syrup.
- Lemon juice
- Adds acidity that helps keep the syrup smooth and prevents crystallisation.
The step that matters
Testing doneness on the stick. Sugar continues to concentrate as it boils, so pulling the pot too early leaves a runny syrup and pulling it too late can make it brittle or scorch. Checking the cracked, non-sticky stick reveals the right concentration.
“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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