Tempering
Tempering has as objectives to ensure product quality and appearance, to allow the treatment of liquid chocolate for different applications (eg demoulding), to ensure viscosity control and to meet the requirements for the net weight. Tempering is also the controlled thawing of meat.
Field of Application
Tempering is used in making chocolate and chocolate-containing products. Chocolate formulations containing cocoa butter or equivalent must be tempered before they are used. This is because cocoa butter can exist in various crystalline forms, which if not tempered, transform into unstable forms, which has a major impact on production capacity and product quality. The tempering process ensures that the crystallization of the fat takes place in stable forms, so that the product can be processed with a good gloss, hardness, bite and postpones the formation of gray-white spots on the surface (fat flower). Poorly tempered chocolate results in the formation of unstable crystalline forms which subsequently cause poor appearance and tissue structure. Chocolate can be tempered too little, well or too much, depending on the specific application.
Techniques, methods and installation
The tempering process involves the melting of all fat crystals present by means of heating to at least 40 ° C, the cooling of the mass usually to below 30 ° C. This allows formation of stable crystalline forms which, upon postponement, bring about a further desired transformation. Finally, the mass is lightly heated to melt away any remaining unstable crystalline forms and to establish further crystallization of stable forms. Depending on the specific recipe or formula, temperatures and waiting times vary to ensure optimal product quality.
a) Tempering with a single stream
Use is made here of the standard technique of accelerating crystallization of the stable forms from liquid followed by changes in temperature. The product is brought into a temper tube by a screw band where it is tempered in three phases.
b) Tempering with a double flow
Here, an already saturated stream (seeded stream) must be brought into a melted and not yet tempered chocolate flow.
c) Temp with multiple phases
This is based on light cooling to produce seed crystals, followed by light heating so that stable crystalline forms can arise. The cooling and heating zones consist of several phases that are kept at the right temperatures via a tilted recirculating water system. Various tempering machines are available based on this principle and are widely used in industry for a range of applications.
