Extracting oil
The craft of oil milling has existed for a long time, the first guild for millers and oil extracters was founded before 1629. At the time, oil mills were industrial mills, in almost 1000 oil mills oil extracters processed 100 to 200 tons of seeds annually. During the season people worked day and night in shifts of sometimes up to 16 hours. Seeds from flax (linseed), rapeseed and hemp were ground and pressed, as well as from beech and walnuts, among others.
From 1850 onwards oil was produced in factories in which steam engines drove hydraulic presses. Thus the craft almost completely disappeared. Thanks to individuals, social organizations and governments, both oil mills, knowledge and skills surrounding the craft have been preserved.
Today, the craft is practiced in the same way as in the past by enthusiastic volunteers. Nowadays there is more attention to safety requirements and hearing protection, in the past oil extracters often became ‘noise deaf’.
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The process
The process of oil milling starts with raw materials such as flax seed, linseed or nuts, and with an oil mill that starts moving. If the mill is powered by wind, the miller turns it on; if it is a water mill, the oil mill does this himself. This sets in motion two large round stones in the mill, the edge stones, which roll over a metal platform. Underneath, the oil exrtracter finely grinds the chosen raw material until flour remains. This flour is heated on a heated plate to about 50 degrees and mixed around. The heat allows the oil to be released from the flour. The warm flour is then poured into bags that are placed between pressing mats and pressure is applied to these full bags using piles and wedges. This causes oil to emerge and can be collected. The residual product remains in the squeezed bags: the ‘cakes’. These are either dried directly into animal feed, or they are pounded and pressed again into flour. Here too, the end product is a cookie.
Oil striking in a water or windmill is a sustainable craft. The oil and residual products are produced in an almost energy-neutral manner and no waste remains.
The oil can be used as a base for soap and paint. Innovative products resulting from the oil include natuleum, an environmentally friendly carboleum, and hardwood oil.
Some mills produce linseed oil in such a way that it is also suitable for human consumption.
Practitioners and stakeholders
Nowadays there is a group of volunteer oil exrtracters who strike oil in the 19 operational wind and water mills in the Netherlands. The volunteer oil exrtracters ensure that the craft is preserved and passed on to a new generation. The public is very welcome when oil is being struck. She can take a tour where a volunteer explains the oil-mining process.
Each oil mill has its own internal training, which is fairly easy to follow. The volunteer oil exrtracters appreciate the craft, among other things, because it takes place in a monument – a historic mill in motion – and because you go from raw material to product in one afternoon: at the end of a shift there is oil and/or linseed oil cakes/linseed meal.
The nomination was made by committed volunteers from the Olie- en korenmolen Woldzigt, Noordmolen Twickel en Oliemolen Eerbeek.
Visit the oil mills of the Netherlands
There are still 20 oil mills in operation in the Netherlands, sometimes maintained and managed by professional millers, but often by volunteers. For the wind and water mills included in this website, you will find the items of the same name in the menu at the top of the website.
Come and see the mills and be amazed by the often beautiful surroundings, the construction, the technology and the story of the millers and oil extracters about their mill and centuries-old profession.
Addition to the Intangible Heritage Netherlands inventory
On December 5, 2017, there was a party for the Dutch millers. The ancient craft of milling has been recognized by UNESCO as Cultural Intangible Heritage. A recognition for an old craft with a bright future. Please see the UNESCO page in this website for more information.
On December 6, 2023, Olieslaan was added to the Intangible Heritage Inventory of the Netherlands. After this new addition, more than 200 forms of intangible heritage have been added to the Intangible Heritage Inventory of the Netherlands, including crafts, festivals and social practices. Entry into the Inventory is a means to help practitioners keep their intangible heritage alive. By adding it to the Inventory, they show that they are working on safeguarding their intangible heritage and working on its visibility.
Three business corridors
Oil can be extracted from flax, linseed, rapeseed and hemp seed and pressed from beech and walnuts, among other things. This happens in the next three operations.
The first business run
The first operation is the crushing of the seed, this is done on the collet corridor. The coller stones (edging stones) crush the seed into flour. The ironer sweeps the splashing seed back under the stones. Once the seed has been sufficiently bruised, the miller lowers the runner and opens the slide, through which the flour falls into the flour container.
The second business run
The second operation is heating the seed flour. Heating is done on the fist. This is a firebox made of stone covered with a steel plate. On top of this lies a bottomless pan in which the seed flour is heated to approximately 40 degrees. For production for consumption no hotter than 43 degrees Celsius, for other production up to 80 degrees Celsius. When the seed flour has heated up, the oil extracter slides the pan with the contents over the funnels, after which the seed flour falls into the two suspended bags (buul).
Below is a sketch explaining how the press bench of an oil mill works.
The third course of action
The third line of business is oil mining. This oil pressing takes place on the press bench. The bagss are placed here between a pressing board and then placed in the pressing bench. By means of a falling hammer, the hammer is driven downwards and driven into the hammer. This puts pressure on the seed flower. This becomes liquid, causing the oil to be squeezed out of the bags and collected in containers.
The final product
The oil always contains dust from the base product. The oil is stored in barrels to settle. This takes several weeks. The oil is then drained above the sediment, resulting in clear oil as shown above. In this case linseed oil.
If oil is preferably stored in a dark place, such as in a cupboard, it can be stored for years without deterioration occurring. Flaxseed oil for consumption can be stored in this way for more than 10 years.