Cold Pressed Extraction, also referred to as Cold Expression, is a method used primarily for heat-sensitive Citrus Peel Essential Oils. In this process the essential oil is obtained first by abrasion or laceration of citrus peels that are subsequently centrifuged to separate the volatile, aromatic molecules from the juice, peel solids and heavier compounds such as waxes and flavonoids. Cold Pressing should be performed quickly to avoid oxidation, hydrolysis or resinification of the essential oil which can occur upon contact with air or water.
While the term ‘Cold Pressed’ can also apply to the process used to extract Carrier Oils (aka ‘fixed’ oils), it is more accurate in this case to refer to the process as Expeller Pressed Extraction. At this time there are no formal legal standards that define what it means to ‘Cold Press’ a fatty oil. Expeller Pressed Extraction is a low-heat process utilized for Carrier Oils that is especially important for preserving vulnerable fats, flavors and nutrients that are susceptible to degradation if exposed to high temperatures. It is a physical process that effectively utilizes a screw press and compression to squeeze oil from the raw material with no added heat. Many sources say that the temperature for this method does not exceed 49˚C (120˚F), but pressure and friction can sometimes raise temperatures from 60˚C up to 99˚C (140˚F – 210˚F).