Name: Chocolate Syrup
Ingredients: 3 tablespoons soluble chocolate; ½ pint boiling water; 1 pint granulated sugar; 1 tablespoon vanilla extract

Why it works: Chocolate and vanilla are a kitchen classic. They rank in the top 5% of all ingredient pairs, and cooks put them together in 10,020 recipes. Both carry sotolon, which smells curry, maple. The science ↓

Chocolate Syrup

Ingredients

3 tablespoons soluble chocolate
½ pint boiling water
1 pint granulated sugar
1 tablespoon vanilla extract

Directions

Make the syrup

In a granite-ware saucepan, combine the soluble chocolate and boiling water, stirring continuously.
Place the saucepan on the fire and stir until the chocolate is fully dissolved.
Add the granulated sugar and stir until the mixture begins to boil.
Cook for an additional 3 minutes, then strain the mixture and let it cool.

Finish and store

Once cool, stir in the vanilla extract.
Bottle the syrup and store it in a cool place.

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.

Chocolate + vanillatop 5% of all pairs

Smell alikemoderate

Cooked together10,020 recipes

Shared aroma: sotolon (curry, maple).
Sugar + vanillatop 8% of all pairs

Smell alikelow

Cooked together35,032 recipes

Shared aroma: beta-damascenone (apple, rose).
Chocolate + sugartop 13% of all pairs

Smell alikemoderate

Cooked together15,404 recipes

Shared aroma: guaiacol (smoky, sweet).

Sugar and vanilla barely smell alike, yet cooks put them together in 35,032 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

Soluble chocolate: Provides the chocolate flavour and colour of the syrup.
Granulated sugar: Adds sweetness and body to the syrup as it dissolves and thickens.

“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.