Fats and Oils: Extraction and Refining

Extracting fats and oils from their sources may be a fairly simple process or a complex one involving several stages.

The best oils from a gastronomic point of view are those extracted simply. The simplest process is cold pressing, as used for ‘virgin’ olive oil and for the best nut oils. The olives or nuts are pressed, and the oil left in the state in which it emerges, with many plant substances present which give it flavour and colour. Unfortunately, these substances include enzymes which attack the oil, so these natural oils do not keep well. However, they are valued for their flavour. Another example of a fat prepared by a natural, simple process which leaves it full of flavour but prone to spoilage is butter.