The moulding of chocolate is technically challenging,and is dependent on the solidification of the constituent cocoa fats into the correct polymorphic form (Form V). This gives a product which is attractive to the consumer as well as possessing good demoulding and bloom resistance properties. Form V is produced following a tempering process involving a complex temperature profile in which seed crystals are produced. However, other polymorphs can nucleate and grow during moulding if the cooling rate is excessive. A computational model has thus been developed to predict the temperature in the mould as a function of space and time. The model uses enthalpy-temperature data obtained over a range of cooling rates. It has been validated using thermocouple data taken from a model mould during air cooling over commercially relevant conditions.