Bühler’s PesaMill™ offers a new high-compression mill for producing Atta flour. The CombiMill is a newly developed process that combines the PesaMill™ with roller mills. The result: The first industrial milling system for the production of authentic whole wheat flour, dark flour for traditional flat bread and standard bakery flour in one milling system.

Bread, long considered a basic stable food, is as diverse as the cultures who consume it. While more airy and thickly sliced bread is preferred in Europe and North America, consumers in North Africa, the Middle East and the Indian subcontinent like flat, wafer-like bread. Depending on the country, these flat breads are based on different recipes and have various names such as Chapati, Roti, Puri, Kissra, Gurassah, Arabic bread, Pita, Lavash and Khoboz.

VARIOUS FLOUR QUALITIES Flat breads are baked from flour with various qualities and characteristics. In India and Pakistan, Atta flour is used for Chapati, Roti, Puri and other bread varieties. This whole wheat flour is characterized by high water absorption and starch damage. Traditionally, Atta flour is ground by stone mills and the relatively high temperatures that are produced in the process are what give the resulting baked flat breads their characteristic taste.

INDUSTRIAL PRODUCTION Stone mills, however, mean high maintenance and energy requirements, and no longer meet today’s food safety standards. This is why stone mills are no longer suitable for the modern industrial production of Atta flour. Originally, Bühler had focused on developing a special roller mill for the industrial production of Atta flour, however, through testing, it quickly became apparent that the typical Atta flour taste could not be achieved with conventional milling technology.

PESAMILL FOR ATTA FLOUR As a result, a completely new milling system for the production of Atta flour was developed: Atta process with PesaMill™. The secret of the new process is the high-compression PesaMill™ which replaces up to twenty traditional stone mills.

As a key component of integrated grinding systems, PesaMill™ is particularly flexible in use. PesaMill™ allows flour characteristics to be flexibly adjusted for individual requirements. Parameters for yield, starch damage and water absorption can be easily, quickly and accurately set for different market requirements.

The grinding material feeds directly to the rolls by using an effective circulation system. For this reason, the grinding gap for the PesaMill™ is wider than for common roller mills. The Atta process compresses the milling product using up to 70 tons of pressure. The enormous pressure and additionally generated shearing force creates heat, which has a positive effect on the typical flavor of the Atta flour, as well as its capacity to absorb water.

EXPANSION INTO COMBIMILL The market success of the PesaMillTM prompted Bühler to look for ways to further enhance the application. The result is the CombiMill process, the first complete industrial milling system for the production of authentic whole wheat flour, dark flour for traditional flat bread and standard bakery flour. The CombiMill process combines the technology of the traditional roller mill with the high-compression PesaMill™, making it possible to produce different qualities of flour on one milling system. Grinding processes can be individually adjusted while remaining true to the recipe, allowing flour characteristics, such as yield, starch damage and water absorption to be flexible adjusted to the market requirement.

COMBINATION OF MILLING TECHNOLOGY The CombiMill process combines the roller mill and the high-compression PesaMill™. Wheat kernels are gently opened by the corrugated rolls of the roller mill, the bran is then separated in the sifter and the produced semolina is finally ground to the desired granulation in the PesaMill™ under high pressure. With its flexible grinding gap adjustment, flour properties, such as starch damage and water absorption, can be easily and precisely fine-tuned. For the production of whole wheat flour or dark flour, the desired amount of bran is added.

INCREASED SANITATION AND REDUCED ENERGY CONSUMPTION All components in the CombiMill process are made from food safe materials and therefore meet the highest level of sanitation. The intelligent design of the PesaMill™ enables easy cleaning and guarantees a high level of food safety. Finally, the PesaMill™ also helps to save energy. The rolls are powered by two direct drives which are composed of a motor and a gearbox transmission, thus allowing energy-efficient operation and reduced energy costs.