Cocoa Mass Milling
There a number of options available for milling nibs into cocoa mass and these include:
- Table top liquidizers for coarse grinding and coarse milling (up to 100g of nibs).
- Table top and free standing mortar and pestle mills of varying capacities (100 – 500g of nibs).
- Laboratory scale melangeurs capable of handling from 200g up to 2.5 kg of nibs.
It is important that the nibs should be gently warmed (not more than 40°C) before milling and equipment such as bowls, pestles, and the stones from melangeurs should be pre- warmed to ensure that the cocoa butter in the sample melts and facilitates grinding. The temperature of the milling mass can be measured using an infrared thermometer and should remain below 55°C. Above this temperature, volatiles are lost at a substantially higher rate—similar to what would occur in full conching. By holding the temperature below 55° C the cocoa mass displays the inherent flavour of the beans without being stripped or reduced as it would be in conching. Should the temperature of the mass rise above this value, the room can be ventilated (cooled) or the mill can be turned off to allow the sample to cool off.
Regardless of the milling equipment used, particle size, as determined by a micrometer, is a critical parameter in determining milling end point. A particle size range between 14 – 25 microns is optimal for effective flavour evaluation since it ensures that all the volatiles in the sample will have been released and that there is no grittiness in the sample which would distract the taster during the flavour evaluation.
More details can be found in Chapter 13 - Processing cacao nibs into mass in “ Guide for the Assessment of Cacao Quality and Flavour” (Cacao of Excellence, 2023) www.cacaoofexcellence.org
The temperature of the milling mass can be measured using an infrared thermometer and should remain below 55° C. Above this temperature, volatiles are lost at a substantially higher rate.
