The cultivated walnut (juglans regia) which belongs to the hard-shelled dry fruits can be found mostly in warm locations of Baden-Württemberg and Alsace. The walnut tree is generally a large and robust tree with a tall trunk probably originating in Western resp. Central Asia. Due to the high amount of linoleic acid, walnuts as well as walnut oil are true specialties of the Upper Rhine and very beneficial to health.
Walnuts contain approx. 63 % fat, whereas the healthy unsaturated fatty acids prevail, followed by 15 % protein and 12 % carbohydrates. They also contain substantial amounts of vitamins, such as vitamin B6 and vitamin E, as well as magnesium. Due to their ingredients nuts are often used as a concentrated food (“trail mix”). Walnuts are consumed mostly during the winter months as dried nibbles. The valuable walnut oil is extracted by means of cold-pressing.
In years of plentiful nut harvest the question arises time and again where oil can be extracted from walnuts. As a special technique is required, there are only a few oil mills that process walnuts. In contrast to the industrial method of winning oil via an extracting agent, these mills extract the oil by cold pressing. Such oils are also called “native” oils because they remain untreated after pressing. The nut kernels are ground and heated to approx. 40 °C; subsequently the oil is extracted from the mash with a hydraulic stamp press. Due to the high content of linoleic acid the oil is very valuable. The palatable, mildly nutty flavoured oil is used for salads and adds a finishing touch especially to root vegetables. In spite of the time-consuming production and the extraordinary quality walnut oil is relatively inexpensive and can be purchased at regional oil mills in the Upper Rhine region.
Source: Dr. Günter Röhrig, LVWO Weinsberg