Name: Hot Lemonade
Ingredients: lemons; ¼ cup sugar; 1 pint boiling water; black pepper

Why it works: Lemon and pepper match in chemistry and in kitchens. They rank in the top 3% of all ingredient pairs, and cooks put them together in 27,047 recipes. Both carry trans-2-nonenal, which smells cardboard, fatty. The science ↓

Hot Lemonade

Ingredients

lemons
¼ cup sugar
1 pint boiling water
black pepper

Directions

Prepare

Cut the lemons in half and remove the seeds.
Squeeze out the juice from the lemons.

Make and serve

In a bowl, combine the lemon juice, sugar, and boiling water.
Sprinkle a little black pepper into the mixture.
Stir well and serve hot.

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 + peppertop 3% of all pairs

Smell alikestrong

Cooked together27,047 recipes

Shared aroma: trans-2-nonenal (cardboard, fatty).
Lemon + sugartop 18% of all pairs

Smell alikelow

Cooked together53,532 recipes

Shared aroma: 2-nonenal (fatty, green).
Sugar + peppertop 32% of all pairs

Smell alikelow

Cooked together19,401 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 juice that gives the drink its sour, bright flavour.
Sugar: Balances the lemon's acidity with sweetness.
Boiling water: Dissolves the sugar and carries the lemon flavour as a hot drink.

“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.