Name: White Fondant
Ingredients: 2½ lbs sugar; ½ cup hot water; ⅛ teaspoon cream of tartar

Why it works: Sugar and cream are a kitchen classic. They rank in the top 9% of all ingredient pairs, and cooks put them together in 43,450 recipes. Both carry 2,3-butanedione, which smells butter, sweet. The science ↓

White Fondant

Ingredients

2½ lbs sugar
½ cup hot water
⅛ teaspoon cream of tartar

Directions

Make the syrup

Combine sugar, hot water, and cream of tartar in a smooth granite saucepan.
Stir the mixture and heat gradually to boiling point.
Boil without stirring until a soft ball forms at 238°F (114°C) when tested in cold water.
Wash off sugar adhering to the sides of the saucepan with a hand dipped in cold water.

Cool and work

Pour the mixture slowly onto a slightly oiled marble slab.
Let it stand for a few minutes to cool, but not long enough to harden around the edges.

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 + creamtop 9% of all pairs

Smell alikemoderate

Cooked together43,450 recipes

Shared aroma: 2,3-butanedione (butter, sweet).

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

Sugar: Forms the sweet body of the fondant and, when cooked to a soft ball stage, sets into a smooth, creamy texture.
Hot water: Dissolves the sugar so it can be heated evenly into a clear syrup before boiling.
Cream of tartar: Acidifies the syrup, helping prevent sugar crystals from forming and keeping the fondant smooth.

The step that matters

Boil without stirring until a soft ball forms at 238°F (114°C). Stirring during boiling can trigger sugar crystallization, making the fondant grainy. Cooking to the right temperature controls the sugar concentration, which determines whether the fondant sets soft and smooth or too firm or too runny.

“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.