Name: Chocolate Icing
Ingredients: 1½ cups powdered sugar; 2 egg whites; 5 tablespoons powdered chocolate, sifted

Why it works: Sugar and chocolate are a kitchen classic. They rank in the top 13% of all ingredient pairs, and cooks put them together in 15,404 recipes. Both carry guaiacol, which smells smoky, sweet. The science ↓

Chocolate Icing

Oven, in the book's wordsA quick oven

Ingredients

1½ cups powdered sugar
2 egg whites
5 tablespoons powdered chocolate, sifted

Directions

In a bowl, combine the powdered sugar, egg whites, and sifted chocolate, then mix until smooth.
Spread the icing on the cake while it is still 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.

Sugar + chocolatetop 13% of all pairs

Smell alikemoderate

Cooked together15,404 recipes

Shared aroma: guaiacol (smoky, sweet).
Sugar + eggtop 21% of all pairs

Smell alikemoderate

Cooked together122,807 recipes

Shared aroma: 2-nonenal (fatty, green).
Egg + chocolatetop 24% of all pairs

Smell alikemoderate

Cooked together11,448 recipes

Shared aroma: 2-heptenal (green).