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Ludwig Keller-Bauer takes a look into the infrared rotary kiln that heats the peanuts before pressing. This results in a better flavour of oil.
Photo: Catrin Cohnen-Deliga
Large sacks of walnuts from Moldova and peanuts from China sit in the storage area. “We press a total of five different oilseeds for our customers,” explains Ludwig Keller-Bauer as he gives us a tour of the facility. In addition to WALA, customers include other natural cosmetics manufacturers, but also companies that sell edible oils as well as animal feed manufacturers that purchase the protein-rich press cakes (the solids left behind after the oil has been pressed out). Naturamus sells any surplus oils at the shop of the WALA-owned Sonnenhof Demeter farm. The farm bakery also takes the macadamia press cakes and uses them to make delicious pastries.
The two smaller oil presses are used to process small quantities of walnuts and apricot kernels from Turkey and Pakistan as well as macadamia nuts from Kenya. Peanuts and Spanish almonds are fed into the larger press. These almonds are also used to make almond flour, which WALA will in future approve for the production of its cosmetics.
The first to use an infrared rotary kiln in an oil mill
The principle of the oil press is simple: A rotating steel screw transports the seeds through a steel cylinder with openings. The screw is shaped in such a way that the distance between it and the cylinder walls gets narrower and narrower, slowly crushing the oilseed until the cells break open and release their oils. Before the seeds enter the large press, they pass through an infrared rotary kiln that can gently warm or toast the oilseeds as required. “With some seeds, the finely toasted aroma is sought after because of the flavour it produces,” explains Ludwig Keller-Bauer, who is also a trained chef. In addition, toasting increases the oil yield. At the end of the process, oil and press cake are collected separately.
Managing Director Ralf Kunert is proud of the infrared rotary kiln. “We are the first to use an infrared rotary kiln in an oil mill,” he tells us. “It allows us to heat the oilseeds to extremely precise temperatures very evenly.” Adjustable temperature setting is essential in the production of almond flour. Whereas in oil production the focus is on maximum oil yield, in flour production the almond pressing process must be less effective – as almond flour needs to retain a fat content of between 15 and 21 percent. “If the almond flour becomes too dry, we have to reduce the temperature in the infrared rotary kiln, among other measures,” explains Keller-Bauer.
Does the oil press have to find its rhythm?
It all sounds simple enough. So it should be able to run all by itself, right? “It takes at least half an hour to properly adjust the machines,” says Martin Geiger, a fourth-generation oil miller. After all, there are three components that need to be aligned: All speeds must be synchronised to avoid back-ups or gaps in the production line, the temperatures have to be just right, and the outflow of oil. Does the oil press have to find its rhythm? “Perhaps more like its flow,” explains Geiger. There are many influencing factors, such as humidity, room temperature and the condition of the oilseeds. Measuring instruments help the four colleagues to check the process – but their ears and noses are just as important. Everyone agrees that if something’s not right, you can usually hear or smell it. The room is filled with the rhythmic sounds of the machines, the blowing of valves. “The apricot kernels sound almost like whale song,” they say. The large press, which comes from France, certainly fills the room with a lot of soul. This is probably why the team gave it a name: Ségolène – after the former French Minister for Ecology.
