How Oils are Produced

Cold extraction oils are usually obtained by pressing and grinding the fruit, seeds or nuts with heavy granite millstones or modern stainless steel presses. The resulting oils retain all of their flavour, aroma and nutritional value. Heat extraction methods include expeller pressing, which involves pressing the fruit, seeds or nuts under extreme pressure, generating heat in the process. Although these types of oil retain much of their flavour and aroma, they are not quite as flavoursome as cold pressed oils.

Chemical solvents may also be used to extract the oil, which is then boiled to remove most of the solvents. Heating the oil to such a high temperature cleanses the oil, but results in a product that has very little of the original flavour, aroma, or nutrients contained in the original seeds or fruit. However, this highly refined oil tends to have a higher smoke point than the unrefined oil (that is, it may be heated to a higher temperature) and has a much longer shelf life.