Chocolate Viscosity – Revisit on the NCA/CMA Method

The National Confectionery Association (NCA) and the Chocolate Manufacturers Association (CMA) jointly developed a method for measuring the yield value and plastic viscosity of chocolates. The NCA/CMA method covers details including sample preparation, viscometer calibration, viscosity measurement, yield value and plastic viscosity calculation. The author recently had an opportunity to closely evaluate this method and has encountered a few issues in its application. After extensive research, the author concludes that the method has mistakenly introduced three parameters including a value, K value, and Xcorr factor. Those values are not only unnecessary but also may introduce artificial errors particularly in calculating the yield value of chocolate. This article shares those findings and intends to inspire more discussion to further improve the NCA/CMA method for viscosity.