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
Combine sugar and water in a pan.
Heat over moderate fire until dissolved.
When warm, add beaten egg white, lemon rind, and juice. Stir well.
Remove scum when boiling.
Boil until perfectly clear.
Strain through muslin.
Shape the sweets
Boil again until a drop in cold water is very brittle.
Pour onto a slab and cut into strips.
Dip hands in cold water and roll and twist the sticks.
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.
-
Sugar + lemontop 18% of all pairsSmell alikelowCooked together53,532 recipes
Shared aroma: 2-nonenal (fatty, green).
-
Egg + lemontop 19% of all pairsSmell alikelowCooked together44,316 recipes
Shared aroma: (e,e)-2,4-decadienal (fatty, deep fried).
-
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
- Forms the clear, hard candy structure once boiled to a high concentration.
- Egg white
- Its proteins rise to the surface and bind impurities, which are then skimmed off as scum.
- Lemon
- Adds acidity and aroma, and its acid helps keep the sugar from recrystallising.
The step that matters
Boil again until a drop in cold water is very brittle. Sugar hardens as its concentration rises and temperature climbs. Stopping too early leaves the candy soft and sticky, while boiling too long can scorch it and turn it bitter.
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.
More barley sugar recipes
You might also like
Lemon Cake228 recipes
Lemon Ice147 recipes
Lemon Sherbet103 recipes
Lemon Custard64 recipesThe free Flavor Lab newsletter: one surprising pairing a week and the molecular reason it works, in 60 seconds. No spam, unsubscribe anytime.
Prefer an account? Create a free account to save pairings and unlock the full chemistry.