Uwe Bindler, recognised expert in the field of chocolate moulding for decades and today active with his engineering office for food technology, has designed a new process, which can also be implemented economically by small manufacturers.
By Alfons Strohmaier
For decades, Uwe Bindler was the Managing Partner of the family-operated company Gebr. Bindler Maschinenfabrik GmbH & Co. KG and one of the leading heads of international chocolate technology. The brothers Heinrich and Hugo Bindler had opened a factory in Freital in Dresden in 1908, specialising in solutions and systems for moulding and moulding chocolate and pralines. After a new start in Bergneustadt, Bindler developed into the leading supplier in this field worldwide from the 1950s onwards, for a long time under the leadership of Uwe Bindler. Numerous patent applications from the 1990s – including for rotational moulding around one or more axes, a new type of dosing mechanism for liquid or pasty materials or an optimised device for the well-known cold stamping process – confirm the spirit of research and creativity of the experienced chocolate expert. After he left the company in 2000, the Swiss Bühler AG took over the enterprise in 2001 and integrated it into the group as the Bühler Bindler business unit.
Since then, Uwe Bindler has been active as a consultant in the chocolate industry and has devoted himself intensively to the subject of complete bean-to-bar chocolate production. The goal was to design a quality-oriented process for chocolate mass production that can be economically implemented by small businesses. In his concept study, the results of which Bindler also presented at the ZDS Congress Inter-Praline, the expert envisages a process in two stages with 60 kg/h and 180 kg/h respectively.
According to Bindler, the solutions known on the market so far to avoid expensive rolling and dry conching have had to accept compromises in taste and processing. Primarily ball mills are used, which achieve a wide range of sizes from < 10 µm to > 25 µm. While the finer parts bind more water and masses becomestougher –sometimes with fluctuating material values – the larger parts become noticeable by granularity. Thin-film reactors are then used in the liquid phase for flavour formation and refinement.
The new solution proposed by Bindler focuses on primary comminution and mixing in one process stage using a cutter from Aalen-based Maschinenfabrik Seydelmann KG. The versatile technology of the cutters offers many other processing possibilities in addition to the size reduction, homogenisation and mixing of masses, for which the traditional company is recognised above all in the international butchery industry .
Bindler has now adapted this technology for the production of chocolate masses. The company supplies the Seydelmann confectionery machines type K64 and K124 for 50 kg to 150 kg of chocolate per hour. In the machine the cocoa nibs with other raw materials are crushed by fast rotating knives. The nibs are filled in batchwise and are crushed to a pasty state. Sugar and milk powder as well as cocoa butter are added in doses. The mixing and conveying movement takes place in the bowl, which also has a temperature control system for cooling and heating and finally also ensures vacuuming. In addition, the process is possible with inert gas (e.g. N2). Bindler points out that the Seydelmann confectionery machine is also suitable for the production of marzipan, fruit and nut masses, mixing pastes as well as for rework processing and pasteurisation.
The test results show that for a mass with 70% nibs and 30% sugar, the comminution to 54µm is done in 10 minutes and the comminution to 121µm in 6 minutes with vacuum. Operation without cooling requires breaks, while the process with cooling is continuous. The metal abrasion is < 1 µg/g nibs; in comparison, the ball mill produces an abrasion of 10 to 30 µg/g nibs.
The cocoa beans are processed into nibs in advance by the mini-winnover up to 150 kg/hour and the roaster, both from Bear Mühlen & Behälter GmbH in Berlin. In detail, the beans are cleaned, thermally pre-treated before winnowing (sifting and breaking) and then roasted in small batches. The Bear cocoa butter press to 3% defatting, scalable from 5 kg/H, guarantees the identity of origin of cocoa mass and added cocoa butter. The cocoa butter thus doesn‘t differ in composition according to origin in taste, material values as well as in crystallisation and solidification.
Prior to dry conching, rolling is an important process stage, which limits the fat content of the mass to 29%. Bindler uses the EXAKT 120S Plus three-roll mill from the company EXAKT Advanced Technologies GmbH for an output of 60 kg/h from 60 µm to 20 µm. The mass is fed directly to the rolls – without ensiling – into the pre-container.
After rolling, the conche is filled directly with the powdered rolling workpieces. In addition to the fermentation and drying of the cocoa beans on the plantations as well as roasting, conching is the most important process for the chocolate flavour. For dry conching, Bindler‘s concept uses modified Seydelmann mixers from the food processing industry, with drives and conching tools adapted accordingly. In addition to cooling and heating, a controlled vacuum can be used for faster deacidification and dehumidification. Seydelmann machine type MR 1300 as conche is designed for 700 kg, the type MR 3500 for 2.400 kg loading. The type MR 1000 is also equipped with a vertical feed.
The chocolate expert Bindler has tested the advantages of the new process in moulding in extensive trials. According to the expert, the process results in an optimisation of taste and texture both in the solid product, in the coating and shell forming and rotation of hollow figures. Controllable flow properties and better protection against migration of filling components are added to the benefits.
