Compound Coating

At Bauermeister, Inc. our confectionery coating systems will assist you in achieving the highest level of product consistency and quality.

• Flexible Capacity with 500 – 8,000 lbs/hr. • of dry material.
• Fine Grinding of particle sizes to meet • your requirements from the finest • chocolates to chocolate icing.
• Significant Fat Savings to achieve • viscosity, better than 2% on some recipes.
• Shorter Conching Cycle and better • efficiency through dry grinding.
• Test Facilites located in Memphis, TN.

Bauermeister, Inc. currently has numerous dry grinding coating systems installed worldwide. These systems produce compound coatings, work exclusively on chocolate or can produce both chocolate and compound.

The principal difference between the two systems is in the mixing/kneading/conching. For compound coatings only one mixer-kneader is required, since the batch time is between 30 and 60 minutes. For chocolate, several kneader-conches are required depending upon the total production rate and the required conching time. The other difference between the manufacture of compound coatings and chocolate is that the latter requires a finely ground chocolate liquor. This can be manufactured using the Bauermeister Shell Con system of cocoa roasting, shell removal and debacterisation, followed by the Bauermeister Cocoa Liquor Grinding process. Alternatively, the chocolate liquor can be purchased on the open market.

A Simple Proccess

The flow chart above shows a typical system for the production of compound coatings. The process is fairly straightforward and starts with weighing and pre-mixing the dry ingredients, such as sugar, milk powder, cocoa, etc. according to the recipe. This procedure can be automated using
pneumatic or mechanical conveying, or by manually dumping the dry ingredients into a weigh scale. From here, the pre-weighed ingredients move into the pre-mixer, prior to entering the grinding
and classifying system which generates a predetermined particle size with a narrow particle size distribution. The finely ground product with the desired particle size passes to the dust collector, whereas, the "overs" or larger particles are returned to the mill for regrinding. The Bauermeister experience has shown that it is preferable for the mill and classifier to remain separate as this gives greater control of the efficiency of both units. In Addition, this also gives better control of the airflow and temperature. The finely ground product then passes into the Kneader-Conche where it undergoes a specific conching process along with the remaining ingredients, such as cocoa butter or vegetable fat, cocoa liquor, lecithin and any other liquid ingredient.

A Semi-Continuous Process

The whole process is semi-continuous. There is a batch process for the dry ingredients weighing and pre-mixing, a continuous operation for grinding and classifying, and finally a batch process for the Kneader-Conches. The whole system is sized in such a way that the mill operates more or less
continually and delivers sufficient ground material to ensure the optimum loading and unloading of the conche with a minimum of downtime. Depending upon the degree of automation in the bulk handling and the PLC equipped control panels, one person can operate this system with subsequent savings in labor costs.

Particle Size Distribution

Controlling the grinding system is fairly simple. In order to change the fineness or to optimize the particle size distribution, there are some variables which can be utilized:
• the total airflow through the grinder and classifier
• the classifier speed
• and the secondary air into the classifier.
Both the particle size distribution and the particle shape are very important to quality issues such as, mouth feel, grittiness and the viscosity of the chocolate. Optimizing the particle size can also mean savings due to a reduction in the excessive use of cocoa butter and lecithin.

The above two graphs show the distribution profile for a 35 micron product from a dry grinding system and a 40 micron product from a 5-roll refiner system.

The dry grinding system has a more even bell curve with a more favorable particle size distribution than that of the 5-roll refined product. The flattening of the bell curve of the 5-roll refined product around 10 microns indicates that the cocoa fibres are not ground further but merely rolled out.

Viscosity & Processing Time

A dry ground product finished in a Kneading-Conche has viscosity and processing time advantages over 5-roll refined material processed in a standard conche. In all chocolate and compound applications to date, major viscosity improvements were found by using the Bauermeister Kneading-Conche vs. traditional conching.

The Kneading-Conche starts out immediately with a heavy paste phase introducing as much energy as possible, but still controlling the temperature. The kneading phase permits the generation of high pressure zones within the paste which, in turn, allows the fat to distribute evenly throughout the dry particles. Moisture is also driven off rapidly during this phase.

The chart above shows a comparison between a milk chocolate manufactured on a conventional 5-roll chocolate refiner and conche, and the same recipe made on the Bauermeister Dry Grinding and Kneader-Conche system. The analysis was conducted by the Frauenhofer Institute for Food Technology in Munich and speaks clearly in favor of the Bauermeister Dry Grinding and Kneader-Conche system.