Cocoa Liquor Grinding & Refining Line
Cocoa liquor, or cocoa mass, is essentially what gives chocolate its brown color. Cocoa liquor is sold as a commodity, often in ‘blocks’ that need to be melted or as a liquid in ‘tanker truck’ loads to chocolate makers that use the cocoa liquor as an ingredient to make their chocolate.
Grinding & Refining
The roasted nib, coming from either the batch nib roaster or the continuous whole bean roaster, are now ready to be ground. Grinding is done in multiple steps know as coarse grinding, intermediate grinding, fine grinding and (sometimes) polishing. It is very important that the grinding is done accurately – a ‘fine’ cocoa mass/liquor is very important for the ‘smoothness’ of the chocolate, the consumer should not be able to feel any grittiness or coarseness. Pre-grinding is typically done in a machine known as a Beater Blade Mill, the intermediate and fine grinding steps in Vertical Ball Mills, and polishing in either a Vertical or Horizontal ball mill.
The most commonly used industry standard for a refined cocoa liquor is to describe it as 99.5% < 75 microns, that means that 99.5% of all the solid particles are smaller than 75 microns, you will not notice any grittiness when tasting it! Polished liquor can be as fine as 20 microns.
Nibrotom Cocoa Nib Pre-Grinder
The Nibrotom pre-grinder is a ‘beater blade’ type mill where an augur feeds the nibs into a grinding chamber whit spinning blades. The only way out of the grinding chamber for the product is through the slotted sieve. From there the coarsely ground cocoa mass is pumped to an intermediate storage tank before further refining
|Beater Blade Mill Type||Capacity (kg / hr)|
|Nibrotom 600||300 – 500|
|Nibrotom 2000||500 - 1,700|
|Nibrotom 3500||1,700 - 3,800|
Beater blade design with 4 specially hardened steel knives
Automatically fed by screw conveyer
Multiple sizes slotted sieves available
Specially designed bearing with ingeneous cooling method
Special cooling ciruits for the walls and bottom
Long life of knives - Industry leading up time
Knife rotation reverses automatically for even wear
Large volume - low velocity suction ensure moisture removal and optimum temparature control
Ability to inject cocoa butter
Modest product temperature increase
Ball Mill – W Series
Both intermediate and fine grinding are accomplished using different versions of the W-90 ball mill.
The intermediate Stage mainly determines the capacity of the fine grinding stage. The better the grinding in the intermediate stage the higher the capacity in the fine grinding stage. In the fine grinding stage, the cocoa liquor is refined down to the required end fineness.
|Ball Mill Type||Capacity (kg / hr)|
|W-70||500 – 3,000|
|W-85||500 – 3,000|
|W-90||1,800 - 3,800|
Robust 90 kW electric motor
Refining action is accomplished by a unique shaft with agitator arms and diverters rotating in a vertical, jacketed grinding tank filled with specially hardened steel balls
Stainless steel chamber and water jacket is designed for optimal cooling and heating
Ball speed at the tips of the grinding arms is highest but almost zero at the periphery of the chamber, which greatly reduces the rubbing effect between ball charge and the chamber wall for a low wear rate
Lehmann Horizontal Cocoa Ball Mill
Lehmann’s horizontal cocoa ball mills are equipped with wear-resistant milling tools and a special milling chamber, designed to ensure continuous, uniform refining. The horizontal and conical grinding chamber allows for homogenous refining without the effect of media clogging certain sections of the grinding chamber. Agitator ball mills are an economic alternative to disc mills for refining of pre-milled cocoa liquor. The highly wear resistant materials of the mill give maximum life span to the grinding tools and guarantee a very low iron intake on the product.
On occasion cocoa liquor can have higher than desired plate counts and off flavors (for instance after poor storage conditions or below standard processing methods). The KSA Cocoa Liquor Treatment system is used for sterilization and flavor optimization of cocoa liquors.
KSA Cocoa Liquor Treatment System
The KSA system is a continuous flow process where the cocoa mass is simultaneously heated, mixed and pressurized before going to a second phase where it is treated with hot air (to dehumidify the product) and exposed to high sheer. A continuous liquor conching step can be added for further flavor optimization, moisture reduction and viscosity improvements. The use of this technology may in certain instances also lead to reduction in conching times during the chocolate production process.
|Liquor Treatment Type||Capacity (kg / hr)|
|KSA500||250 – 500|
|KSA1000||500 - 1,000|
|KSA2000||1,000 - 2,000|
Continuous process combining, mixing, heating, pressure, moisture addition (and removal) and high sheer.
Sudden release of high pressure imposed on the cocoa liquor ensures rapid and significant reductions in
Depending on initial plate counts deactivation rates can be 3 logs or more (typically 75% of the incoming load).
Improvement in flavor of the cocoa liquor
Improvement in viscosity of the cocoa liquor
AMC Cocoa Blocking Line
The Duyvis tempering and filling systems are made specifically for the blocking-off of cocoa butter and cocoa liquor. The system can also handle most other fats and oils.
The tempering is based on the counter-flow principle. The cooler consists of one and up to four cooling reactors with internal rotating scrapers. A frequency controlled pump moves the product through the cooling tubes. The scrapers thoroughly mix the semi-crystallized mass away from the chilled cooling reactor surface.
The boxes are automatically filled to the exact weight. After approximately 5 to 20 minutes (for cocoa butter and cocoa liquor respectively), the product in the box is fully solidified and can be closed, transported and palletized.
During the short time it takes to transport the full box and replace it with a new empty box, the filling valve is closed and the product temporarily flows into a small buffer vessel. This buffer empties itself when the filling is started again, thus saving filling time and energy.
|Liquor Blocking Type||Capacity (kg / hr)|
|AMC3000||500 – 1,650|
|AMC5500||1,650 - 3,000|
|AMC7500||3,000 - 4,000|