Tempering

Chocolate samples for flavour evaluation can be assessed as either un-tempered or tempered pieces. Tempering produces a uniform sheen, sharp ‘snap’ and crisp ‘bite’ in the chocolate pieces and results from consistently small/dense cocoa butter crystals in the product.

The fats in cocoa butter can crystallize in six different forms (identified using Roman numerals I to VI) at different temperatures and each of the six different crystal forms has different properties. 

Well tempered chocolate has the largest number of the smallest sized type V crystals possible which provides the best appearance and texture. Type V crystals are also stable so texture and appearance will not degrade over time.

The careful manipulation of temperature during the cocoa butter crystallization process to accomplish tempering can be achieved by 

1. manually using a marble slab, 
2. using a double boiler,
3. using a small table top tempering machine or 
4. using pre-crystallized cocoa butter.

Regardless of the process and equipment used, the chocolate must first be heated to 45° C to melt all six forms of crystals. 

Next, the chocolate is cooled to about 27° C which will allow crystal types IV and V to form. At this temperature, the chocolate is agitated to create many small crystal “seeds” which will serve as nuclei to create small crystals in the chocolate. 

The chocolate is then heated to about 31° C to eliminate any type IV crystals, leaving just type V. 

After this point, any excessive heating of the chocolate will destroy the temper and this process will have to be repeated. Moulding and cooling into small bars or pieces immediately follows tempering.

Refrigerators and air conditioned rooms are often used to cool filled chocolate moulds but both need to be checked prior to use to ensure they are neutral smelling and do not contain any off odours.

Chocolate (particularly semi-sweet chocolate) will change its flavour profile over time, particularly mellowing with long term storage. While this is recognized, it may not be practical to hold the chocolate 2-4 months following creation to allow this to happen before assessment.

More details can be found in Sections 14.4.4 – Tempering the chocolate and 14.4.5 Moulding of chocolate in the Guide for the Assessment of Cacao Quality and Flavour” (Cacao of Excellence, 2023) www.cacaoofexcellence.org