Tempering Degree

The production and quality of chocolates were strongly influenced by the pre-crystallization process (tempering). Tempering is performed in so called tempering machines, and the intensity of pre-crystallization may be defined as tempering degree. Only after optimum tempering finished chocolates receive their fine gloss, melt, snap, heat stability and bloom resistance. In the tempering process seed crystals were developed within the slightly cooled chocolate melt. These seed crystals shall work as a starter material for crystallization after further cooling within the cooling tunnel. The pre-crystallized chocolate mass has to be fluent enough to easily be pumped and deposited. Only the thermodynamically stable crystal form ß(V) of cocoa butter is workable for chocolates of enough resistance against fat bloom. Bloom tendency means a serious problem for many chocolate producers. High production speed and longer distribution ways seem to be actual reasons for increased bloom tendencies. The quality of chocolates and confectionery may be verified under optimized tempering and cooling, only.

Pre-competitive research is necessary for

• Better instrumental control of tempering machines
• To correlate tempering degree and flow properties as well as crystallization speed of tempered masses within the cooling tunnel
• To increase bloom stability by an optimized pre-crystallization process.

Under the economic aim of an ensured product quality our project has the following scientific aims:

• Measurement of quantity of seed content within tempered chocolate masses (tempering degree)
• Influence of tempering degree on crystallization speed within cooling tunnel
• Influence of tempering degree on flow properties of chocolate masses
• Influence of tempering on bloom resistance.