Making a chocolate bar begins with mixing the ingredients and grinding them to give a mixture of correctly sized particles. Size is critical to the 'mouth feel' of the product, and is typically about 0.02 mm. The next stage is known as 'conching' and involves removing volatile compounds and adjusting moisture content and viscosity. This gives the end product its desired flavour. The mixture is melted, sheared (stirred) and cooled in a complex process known as tempering. The temperature and shearing have to be very carefully controlled or the chocolate ends up brittle, crumbly and tasting different. This experiment models the process