Name: Orange and Lemon Syrup
Ingredients: 1 pint orange and lemon juice; 2 pounds sugar; Rind of oranges and lemons

Why it works: Orange and lemon match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 10,634 recipes. Both carry 3-hexenal, which smells apple, fruity. The science ↓

Orange and Lemon Syrup

Ingredients

1 pint orange and lemon juice
2 pounds sugar
Rind of oranges and lemons

Directions

Prepare and boil

Grate the rind of the oranges and lemons.
Mix the grated rind with the juice.
Boil the mixture.

Strain and bottle

Strain through a flannel bag.
Bottle the syrup when cool.

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.

Orange + lemontop 1% of all pairs

Smell alikestrong

Cooked together10,634 recipes

Shared aroma: 3-hexenal (apple, fruity).
Lemon + sugartop 18% of all pairs

Smell alikelow

Cooked together53,532 recipes

Shared aroma: 2-nonenal (fatty, green).
Orange + sugartop 20% of all pairs

Smell alikelow

Cooked together19,212 recipes

Shared aroma: beta-damascenone (apple, rose).

Lemon and sugar 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: Provides sweetness and body, thickening the syrup and helping it keep.
Orange and lemon juice: Adds tartness and fresh citrus flavour that balances the sweetness.
Orange and lemon rind: Contributes aromatic citrus oils that give the syrup its fragrance.

“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.