Name: Butter Scotch Squares
Ingredients: 8 cups sugar; 3 cups glucose; 2 quarts water; ¼ teaspoon salt; 1 pound butter; 1 teaspoon vanilla extract

Why it works: Sugar and vanilla are a kitchen classic. They rank in the top 8% of all ingredient pairs, and cooks put them together in 35,032 recipes. Both carry beta-damascenone, which smells apple, rose. The science ↓

Butter Scotch Squares

Ingredients

Directions

Make the caramel

In a large pot, combine sugar, glucose, and water.
Cook the mixture over medium heat until it reaches 300°F (150°C).
Add salt and butter, stirring quickly until the butter dissolves.
Remove from heat and stir in vanilla extract.

Shape and serve

Pour the mixture onto a greased surface and spread it as thin as possible.
Use a caramel cutter to mark the surface both ways.
Allow to cool and then break apart into squares.

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 + vanillatop 8% of all pairs

Smell alikelow

Cooked together35,032 recipes

Shared aroma: beta-damascenone (apple, rose).
Butter + vanillatop 14% of all pairs

Smell alikemoderate

Cooked together20,050 recipes

Shared aroma: guaiacol (smoky, sweet).
Sugar + buttertop 17% of all pairs

Smell alikemoderate

Cooked together98,233 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

Sugar: Provides the bulk of the sweetness and forms the crisp, brittle structure as it cooks.
Glucose: Inhibits sugar crystallization, keeping the candy smooth and preventing grainy texture.
Butter: Adds fat for richness and a tender bite, and contributes to the buttery flavour.

The step that matters

Cooking to 300°F (150°C). Sugar syrup's final texture depends on its temperature. Undercooked mixtures stay sticky and soft, while overcooked ones turn bitter and burn. Reaching the target temperature controls how hard and brittle the candy sets.

“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.