Linseed oil: What does cold pressed mean?
Today, linseed oil is offered in many supermarkets, health food shops, organic food shops, as well as in pharmacies. And at first glance, all linseed oils seem comparable. It is therefore worth taking a closer look. Because linseed is one of the native plants that contains the highest proportion of the particularly valuable omega-3 fatty acids. These polyunsaturated fatty acids are particularly sensitive and therefore not exactly the favourites of supermarkets - unless they are refined or preserved with preservatives. However, for the sake of your own health, you should avoid such products.
Cold-pressed linseed oil
Cold-pressed linseed oil is usually obtained by a screw press. In this process, the seed is pressed through a press cylinder with the help of a screw roller. The nozzles at the end of the outlet, but also the pressing speed, have an influence on the oil yield and especially on the quality. In cold pressing, oil temperatures of maximum 40° C are reached.
The term "cold pressed" means that no artificial heat may be added during the pressing process, which could accelerate the pressing process. But here, too, the difference lies in the detail. For it is well known that pressure also generates heat. And so oils with a lot of pressure can quickly reach a temperature of 60 degrees and more. Advantage: You gain time and high pressure also means that more oil is extracted from a kilo of seed. Disadvantage: Many valuable ingredients are already destroyed during pressing as the temperature increases.
Flax seeds are rich in polyunsaturated fatty acids, above all the omega-3 fatty acids and accompanying substances such as vitamin E, sterols, mucilage or vitamin B. The oil is also rich in vitamin E. High pressing pressure produces high temperatures and this increases the tendency to oxidation. This also applies to the presence of oxygen or light. Light is energy and the incidence of light also supports the tendency to oxidation, as the light particles interact with the fatty acids.
Fresh linseed oil
Georg Gilli of the Gilli oil mill in the Weinviertel region of Lower Austria therefore personally checks the temperatures during pressing on a regular basis. For him, it is crucial where exactly the measurements are taken. Because the oil cools down again quickly after pressing and there are "margins" here too. But not for Georg Gilli. While the average oil yield is around 30-40 per cent per kilogram of linseed, he gets just 25 per cent yield, which is due to his particularly gentle pressing. This preserves the essential fatty acids, vitamins and flavours. This is why the Gilli oil mill has already received several awards for the taste of its linseed oil. A reduced yield of 25-30 percent per kilogram compared to other pressings is therefore an essential quality and also price criterion for him.
For Georg Gilli, three criteria are relevant for good taste and high quality. This begins, of course, with the selection of the flax and its proper cultivation. He gets the linseed from the field of organic farmer Karl Hogl in the Weinviertel (Lower Austria), only 5 kilometres away, who cultivates his linseed field with great care and regularly takes samples to check for optimal ripeness. The second criterion for him is the particularly gentle pressing with personal supervision described above. Equally important is then the treatment after pressing, where the aim is to remove the suspended matter. This is done by storing the wine for a sufficiently long time so that the suspended matter can settle. There is little time for this, as the linseed oil should be enjoyed as fresh as possible. In the case of Saint Charles Fresh Linseed Oil, which is pressed exclusively for Saint Charles on a monthly basis, it only takes a few days from pressing until the oil is ready to be bottled and sold.
Good things take time
Good quality is created with a lot of passion and by giving things time. Georg Gilli wants to produce the best quality - and knows that high quality takes time. Just like the witnesses of his family history - the 460-year-old walls of the oil mill, which he lovingly restored and which today are a sign of true durability.
Cover photo: Copyright Klaus Vyhnalek