Name: Hard Sauce
Ingredients: 1 cup sugar; ½ cup butter, softened; 1 egg, yolk and white separated; Lemon, vanilla, or orange for flavoring

Why it works: Butter and lemon are a kitchen classic. They rank in the top 16% of all ingredient pairs, and cooks put them together in 41,227 recipes. Both carry 3-hexenal, which smells apple, fruity. The science ↓

Hard Sauce

Ingredients

1 cup sugar
½ cup butter, softened
1 egg, yolk and white separated
Lemon, vanilla, or orange for flavoring

Directions

Make the sauce

Beat the butter and sugar together until creamy.
Add the yolk and white of the egg, beaten separately, and stir well.
Flavor with lemon, vanilla, or orange as desired.

Chill and serve

Set the mixture in a cool place until ready to serve.

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.

Butter + lemontop 16% of all pairs

Smell alikemoderate

Cooked together41,227 recipes

Shared aroma: 3-hexenal (apple, fruity).
Butter + eggtop 17% of all pairs

Smell alikemoderate

Cooked together118,967 recipes

Shared aroma: decanal (soap, orange peel).
Sugar + buttertop 17% of all pairs

Smell alikemoderate

Cooked together98,233 recipes

Shared aroma: guaiacol (smoky, sweet).
Sugar + lemontop 18% of all pairs

Smell alikelow

Cooked together53,532 recipes

Shared aroma: 2-nonenal (fatty, green).
Egg + lemontop 19% of all pairs

Smell alikelow

Cooked together44,316 recipes

Shared aroma: (e,e)-2,4-decadienal (fatty, deep fried).

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

Butter: Creams with the sugar to form a smooth, rich base for the sauce.
Sugar: Sweetens the sauce and, creamed with butter, gives it a light, fluffy body.
Egg: Adds richness and body to the sauce as it is stirred into the creamed mixture.