The oil is produced by crushing the seeds or by grinding them, then mixing them with water and distilling them. The white mustard generates a yellowish coloured, pungent oil, whereas the black mustard produces a lighter coloured and stronger tasting oil. Direct pressing the seeds yields a simple mustard oil preparation. This produces a mustard oil with a strong flavour. Crushing the seeds and then separating the oil is another way to make mustard oil. Mustard oil and meal are produced by both extraction methods. When mustard seeds are processed in a mustard oil plant, a by-product is created in the form of seed pressed cakes, which contain very little oil. These cakes from the distillation process are used to make oil cakes, which are then fed to animals. The oil cake is left over after the production process provides 37% oil.
