The science of what makes chocolate good has been revealed by researchers studying a 140-year-old mixing technique. Scientists have uncovered the physics behind the process – known as conching – responsible for creating chocolate's signature smooth texture.
A team led by the University of Edinburgh studied mixtures similar to liquid chocolate made using the conching process, which was developed by Swiss confectioner Rodolphe Lindt in 1879. Their analysis, which measured the density of mixtures and how they stages of the process flowed, suggesting that conching may alter the physical properties of chocolate's microscopic sugar crystals and other grainy ingredients. Until now, the science behind the process was poorly understood.
The new research shows that conching – which takes several hours to mix ingredients – creates smooth melted chocolate by breaking chunks of ingredients into finer grains and reducing friction between particles.
Before the invention of conching, chocolate had a grainy texture. This is because the ingredients form rough, irregular clumps that don't blend smoothly when mixed with cocoa butter using other methods, the team says.
