Grinding cocoa nib into liquor prior to refining improves the refining process. The Cacao Cucina® Nib Grinder is an impact hammer mill, supplied with three grinding screens. The hammers and screens are hardened by a patented process to improve wear and minimize metal in the product. The machine has a variable speed drive, controlled by a keypad on the control panel. The Grinder infeed is guarded, and there is an E-Stop on the control panel for safety.
The grinding screens have different size holes, and are easily interchangeable. Winnowed nib is first fed through the grinding screen with the largest hole openings. The coarse powder from the first grind can then be fed through the grinding screen with the medium hole openings, resulting in a liquor paste, as fat begins to release from the nib. A third pass can be made through the grinding screen with the small hole openings, yielding a fluid liquor typically below 200 microns.
Why take a gradual, step-wise approach to nib grinding? Grinding the nib in stages reduces the heat impact on the liquor from the grinding process. There are faster methods of grinding nib, but the resulting liquor may also experience much higher temperatures from the shear. We don’t want to expose our perfectly roasted nib to high temperatures in the grinding process.
Another interesting design element of our Nib Grinder is that the gradual particle size reduction is being performed in the presence of air. As the nib is transformed into liquor, the operator may often notice a strong, acidic aroma. This is somewhat of a pre-conching action, as acid formed in fermentation are driven off with friction and low heat.
So, why use the Nib Grinder at all? What not put nibs in the Chocolate Maker?
The Nib Grinder processes large nibs into liquor more efficiently than the Chocolate Maker, or a ball mill. Grinding nib prior to refining results in faster, more uniform particle size reduction. Introducing a fluid liquor in the refiner allows you to process a batch of chocolate in the Cacao Cucina® Chocolate Makers below 20 microns in an average of eight hours (based on our tests of 65% dark chocolate with granulated sugar). However, you may choose to start mixing and refining your chocolate from the coarse powder or liquor paste, depending on how much time, heat and grinding time you want to use in making your chocolate recipe.
Nib Grinder Custom Options
Although we have standardized on three basic screen sizes for the Nib Grinder, we can fabricate custom screens for nib that displays unique grinding properties. Between the variable speed drive and the design of the screens, the operator has flexibility and control in the process of grinding nib into liquor, while minimizing the heat impact on the liquor and imparting a pre-conching effect on the liquor.