Why it works: Lemon and butter are a kitchen classic. They rank in the top 16% of all ingredient pairs, and cooks put them together in 41,227 recipes. Both carry 3-hexenal, which smells apple, fruity. The science ↓
Barley-sugar
Ingredients
Directions
Prepare
In a pot, combine the sugar and spring water.
Add the egg white to clarify the mixture as directed in previous recipes.
Cook the sugar
Once it begins to whiten and thicken, stir in the lemon juice.
Boil quickly until it reaches the desired consistency.
Add a few drops of essence of lemon just before removing from heat.
Shape and store
Pour the mixture onto a marble slab or a shallow dish greased with butter.
When it starts to harden at the edges, shape it into sticks, lozenges, or balls.
For other uses, keep the mixture warm in a water bath until needed.
Store cooled sugar in dry canisters to prevent moisture absorption.
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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Lemon + buttertop 16% of all pairsSmell alikemoderateCooked together41,227 recipes
Shared aroma: 3-hexenal (apple, fruity).
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Egg + buttertop 17% of all pairsSmell alikemoderateCooked together118,967 recipes
Shared aroma: decanal (soap, orange peel).
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Sugar + buttertop 17% of all pairsSmell alikemoderateCooked together98,233 recipes
Shared aroma: guaiacol (smoky, sweet).
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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).
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 once cooked to the desired consistency.
- Egg white
- Clarifies the syrup, binding impurities so they can be skimmed away for a clear candy.
- Lemon juice
- Adds acidity that brightens flavour and helps limit crystallisation of the sugar.
The step that matters
Boil quickly until it reaches the desired consistency. Sugar syrup hardens according to its final temperature, so overcooking gives a brittle, bitter result and undercooking leaves it sticky. Boiling briskly keeps the time at high heat short and the colour pale.
Swap the lemon
How well each one fits the dish's main ingredients (sugar, egg, butter):
- Vanillafits better
- Lemonthe original
- Raisinfits about as well
- Figfits about as well
Fit is the average pairing score against sugar, egg, butter. 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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