The exact science of making smooth fudge explains why heavy construction materials suddenly crack and fail.
Fudge is a concentrated suspension of sugar crystals in a sugary liquid. The transition from soft, chewy candy to hard, brittle chunks is driven by the volume of these crystals. This same physical math governs how materials like wet concrete or industrial slurries transition from being ductile to brittle. By studying the cooking of crystalline candies, researchers found a universal law for how solids break under stress. It means that the secrets to better infrastructure might be hidden in the recipes used by confectioners. This provides a new way to monitor the safety of bridges and buildings by looking at the ratio of internal particles.
Cooking crystalline candies and the ductile to brittle transition in concentrated suspensions
arXiv · 2605.06513
The existence and origin of the ductile to brittle transition in non-Brownian suspensions and pastes is underexplored despite the ubiquity of such materials in practical applications. We demonstrate the phenomenon in candies of sugar crystals in a water-protein-fat matrix prepared by boiling a sugar-cream-butter mixture (known as 'fudge' in some countries). As cooking time or final cooking temperature increases, we observe a transition from a fluid to a ductile solid, then to a brittle solid tha