Name: Lemon Syrup
Ingredients: 2 lbs loaf sugar; 2 pints water; 1 oz citric acid; 1/8 teaspoon essence of lemon

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 ↓

Lemon Syrup

Ingredients

2 lbs loaf sugar
2 pints water
1 oz citric acid
1/8 teaspoon essence of lemon

Directions

Make the syrup

Boil the sugar and water together for 3 hours.
Pour the mixture into a basin and let it cool.

Flavour and bottle

Beat the citric acid to a powder and mix it with the essence of lemon.
Add the citric acid mixture to the syrup and mix well.
Bottle the syrup for use.

Recipe from a historical cookbook (Internet Archive).

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 pairs

Smell alikelow

Cooked 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

Loaf sugar: Provides sweetness and the body of the syrup as it dissolves in the water.
Citric acid: Adds sourness that balances the sweetness and gives the syrup its lemon tang.

“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.