After harvesting, grain is contaminated with soil, straw and small stones. It must, therefore, be thoroughly cleaned before storage. During the pre-cleaning stage, straw and any metal parts are sorted out and removed. The grain is carefully cleaned over several stages. The separator screens out everything that is larger or smaller than healthy grain. In the aspirator, lighter particles, such as straw or dust, are sorted out by airflow. The destoner separates stones from the grain and removes them. The trieur sheet sorts out all components not shaped like the specific grain, e.g. other types of grain or weed seeds. In addition, a colour sorter uses cameras to detect discoloured and unusable grains and selectively blow them away with compressed air. The scourer frees the grain of any residual dirt and dust and removes the external parts of the husk. After these cleaning stages, the grain is prepared for milling.
Before the milling can proceed, the grain is sorted by quality and mixed together in a mixing cell. When it comes to milling, the roller mill is the most important machine in the flour mill. In it, the grain is gently crushed between two steel rollers. The grains are broken up and the endosperm is separated from the husk. The flour and husk parts are then separated with the help of sieves. This process is repeated several times until the desired flour type is achieved. Over further milling stages, the last remaining flour particles are removed from the husk and finely ground. Each grinding process produces grain particles of various sizes.
Our plansifter, which consists of a stack with more than 20 sieves of different mesh sizes arranged one above the other, sorts the milled material. The larger to medium-sized grain particles that remain on the screens are re-processed in the roller mill. This successive grinding and sieving is referred to as the “passage”. This passage is repeated until the desired degree of separation of husk and flour particles is achieved. The various milled products – meal, semolina, medium-coarse grain flour and flour – are stored in silos according to quality. In addition, flakes, bran and germ buds are also classified among other mill products.
All finished mill products – meal, semolina, medium-coarse grain flour, flour, flakes or bran – are sorted by quality and stored initially in silos. Before filling, the cereal products are subjected to a further, careful inspection. Flours, flakes and cake mixes are filled into paper and film bags or folding cartons with individual grammages for the food retail industry. Every day, we pack around 100,000 packages for private households. To supply bakeries, wholesalers and the food industry, cereal products are transported in sacks or so-called “Big Bags” weighing between 10 and 750 kg, or in bulk in silo trucks. The baking industry uses these to make hundreds of different types of bread, rolls or pastries. In the food industry, grains are processed into products such as muesli, crispbread or sweets.
We monitor the quality of the grain throughout the entire processing operation. As early as at the point of delivery, the grain is checked for its cleanliness and product safety. The necessary quality tests and checks of the grain’s properties are run in our laboratory. The grain is tested for its purity using a detailed analysis. To this end, all the components of the sample that are not otherwise part of a flawless grain are sorted out and weighed. The lower the level of foreign matter, straw or broken grains, the better the raw material meets the requisite quality criteria such as shelf life and hygiene. In addition, protein content, grain hardness, sedimentation value and moisture are measured, and we also carry out a visual and sensory control of the cereal grains we receive. Further tests are conducted in our laboratory, for example, to ensure the desired baking properties of our flours. The dough, kneading and baking properties of our flours are put through a number of practical tests in our application technology department. This makes it possible to determine whether the flours actually have the required properties for baking, such as the correct malleability of the dough. Careful cleaning of the grain is essential for all subsequent phases of processing. This is supported by a high-tech device – our Sortex colour sorter. All the processes in our mill are steered and monitored from a control centre. Grain kernels and cereal products are stored under constant storage conditions. Precisely dosed ventilation and the monitoring of temperature and humidity maintain the grain’s high quality during storage.
To us, it goes without saying that sustainability also means using resources carefully. To generate electricity, we rely, among other things, on photovoltaic energy from the south side of the mill tower. Furthermore, our modern energy management system ensures the energy-efficient use of resources.
The delivery route taken by the grain, from the contract farmers' fields to the mill, is characterised by the short transport distances: SchapfenMühle works with over 600 farmers and accepts grain only from sustainable, value-conscious suppliers. Cultivation contracts with suppliers from the region guarantee high product safety and quality for us. Almost all the grain components are used in production. Various milled products are produced during the milling process. Roughly 80 percent of the resulting products include flour, flakes, meal, semolina, medium-coarse grain flour and bran. The remaining 20 percent or so consists of feed bran, feed or coarse flour and is used as animal feed. Just half of one percent of the grain (or thereabout) that we receive is disposed of as waste. These are, for example, stones or other impurities contained in the threshed grain. Our “Blühwieseninitiative” (“Flowering Meadow Initiative”) shows how important sustainability and species conservation are to us. By planting at least 100 m2 of flowering meadow per hectare of wheat, our contract farmers are supporting an initiative to prevent the extinction of bees, thereby contributing to species preservation.