Name: Lemonade, No. 2
Ingredients: 4 lemons; 1 pint boiling water; 1 cup sugar; 1 cup water; additional sugar and water to taste

Why it works: Lemon and sugar 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 ↓

Lemonade, No. 2

Ingredients

Directions

Prepare

Peel the lemons.
Pour boiling water over the peel of one lemon.

Make the syrup

Make a syrup by boiling sugar and water for 10 minutes, then skim.
Pour the syrup over the infused lemon peel.

Finish and cool

Squeeze in the lemon juice and adjust sweetness with more sugar and water as desired.
Cool the mixture on ice.

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.

Lemon + sugartop 18% of all pairs

Smell alikelow

Cooked together53,532 recipes

Shared aroma: 2-nonenal (fatty, green).

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

Lemons: Provide the tart acidity of the juice and the aromatic oils from the peel.
Sugar: Balances the lemon's acidity with sweetness and dissolves into the syrup.

“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.