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 ↓
Barley-sugar
Ingredients
Directions
Make the syrup
Boil the sugar until it reaches the crack stage.
Add lemon juice, vinegar, or dissolved alum to prevent graining.
Remove from heat and dip the pan in cold water to stop cooking.
Shape the sweets
Pour the sugar onto a marble surface rubbed with oil.
Cut the sugar into small pieces with scissors.
Have an assistant roll the pieces out quickly to ensure uniform size.
Optionally, add a drop of essence like citron for flavor.
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
- Sugar
- Forms the glassy, hard candy structure as it cooks to the crack stage.
- Lemon juice
- Acid helps prevent the sugar from crystallising, keeping the candy smooth and clear.
The step that matters
Boil the sugar to the crack stage. Sugar must reach the correct temperature for the candy to set hard and brittle. Too little cooking leaves it sticky, while overcooking can scorch or turn it bitter. Adding acid helps prevent graining during boiling.
“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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