Cocoa Butter - why does it crystallize?
Cocoa butter has a complex crystallization system. It is polymorphic which means it has the ability to crystallize in several different forms according to how the liquid fat is solidified. The different crystalline forms are characterized by differences in the distances between the chains of glycerides and their angle of tilt.
There are 6 main polymorphic crystalline forms: I (or gamma form) (melting point 17°C) is created by rapid cooling of the liquid fat but it is unstable and can rapidly transform to II (or alpha form) (melting point 21-24°C) and this form can change more slowly to forms III and IV (or beta prime form) (melting point 25-29°C). Form IV would generally be produced if untempered or poorly tempered chocolate were cooled. This form changes rapidly to Form V (or beta form) (melting point 34-35°C) which is stable and is the state produced in a well tempered chocolate. Form V very slowly transforms into form VI and it may be accompanied by fat bloom.
If crystallization takes place in chocolate which has already set, it can cause cracks to appear in the chocolate which dulls the surface. If there are temperature changes during the storage of chocolate it can cause the crystal structure to change which can cause cracking and/or fat bloom.
In soap and toiletry making stability is important, otherwise the quality is poor and fat bloom develops, this is achieved through tempering or controlled crystallization.
How is Cocoa Butter Deodorized?
The cocoa butter is deodorized via steam being injected into the melted cocoa butter to "drive off" the volatile components which contribute to the odor. The product is then treated with diatomaceous earth (clays) which remove the color agents (it is basically an extremely fine filtration process) to create a nice, white butter. This is a process similar to our shea butter refinement.