Chocolate brings a little bit of luxury into everyday life. It has lost none of its seductive allure over the centuries. Even stubborn people cannot resist its temptation, as tellingly shown by the film Chocolat in which sweet creations cast a spell over an entire provincial town.
This taste sensation is the product of a rather ordinary manufacturing process. The cocoa beans must be fermented and roasted, then comes the grinding and conching of the cocoa mass. How smoothly the finished chocolate melts and how it feels in the mouth is decided way back in the grinding process. Even tiny particles can be detected by the human tongue; therefore, the finer the consistency, the creamier the end product.
In order to achieve an optimal result, the chocolate mass is put through a rolling system at different temperatures and revolution speeds. The pressure on the mass is continuously increased and by the end of the process, the particles are so small that the coating thickness on the metal cylinders is only about 20 micrometers. Even with particle sizes in this range, there is still a wide variety of flavors. The Japanese prefer chocolate with a particle size of 11 micrometers, the Swiss allow 16 and for the Americans, it can be up to 20 micrometers.
A spectrometer from Carl Zeiss allows the coating thickness of the chocolate and therefore the particle size to be decided with micrometer precision and without contact – right in the grinding process. The reflectance of the mass in relation to the wavelength is measured in the near infrared range (950 to 1,700 nanometers), which delivers the specific reflection spectrum. Continuous, second-by-second measuring allows every step of the grinding process to be followed very closely. Thus, the taste sensations that lie in store for chocoholics are already determined during production.
April 18, 2012