The manufacturing methods of rapeseed oil sold In Finland differ significantly. The method used has a major impact on the quality and composition of the oil. Of the methods, cold pressing is the most gentle and natural; extraction and hot pressing are the other methods available.

Cold Pressing
Oil is extracted from selected rape seeds by mechanical pressing. The seeds are neither heated nor treated chemically. The gentle method ensures that the fatty acid composition and vitamins of the oil are preserved in their natural form. Cold pressing saves energy and the environment because the production does not generate waste and emissions. The compressed seeds are used as protein feed for animals.

Extraction
Extraction is the most commonly used method. The seeds are heated and the oil is extracted by means of solvents. After the extraction, the solvents are distilled off. After that, the oil is refined using heat and chemicals. The process removes the lecithin, and part of the flavonoids and vitamins are also lost.

Hot pressing
The seeds are compressed in two stages and heated. The oil obtained is refined using heat and chemicals. The rate of refinement varies at different mills. The final cleaning does away with some smell, taste and colour.