In actuality, there may be no difference between cold-pressed flaxseed oil and virgin flaxseed oil. The terms aren't mutually exclusive. You can purchase flaxseed oil products that are both cold pressed and virgin.
Cold Pressed Oils
"Cold pressed" is a term used to describe the way cooking oil is extracted from its source. The process involves the use of heavy granite millstones or modern presses made of stainless steel to press and grind fruits and seeds to extract their oils. The process generates heat through friction, but in order for an oil to be classified as cold-pressed, this heat must be kept below 120 degrees Fahrenheit.
When used to describe cooking oils, the terms virgin and extra virgin refer to acidity levels rather than extraction methods. Extra virgin oils have an acidity level of 1 percent or less, while virgin oils have an acidity level no greater than 2 percent. These differences affect the taste and cooking applications of an oil. Flaxseed oil can be both cold-pressed and have an acidity level between 1 and 2 percent, which qualifies it as virgin oil.
Although the website "The Nibble" claims that the term cold pressed and expeller pressed are synonymous, author Lee Faber disputes this in her book "Healthy Oils." Faber explains that expeller pressing involves the use of extreme pressure that generates far greater temperatures than are created by cold-pressing.
Flaxseed oil is created using low or no heat. When heat is applied to flaxseed oil, its omega-3 fatty acids can be destroyed, thus eliminating the health benefits of these cardioprotective nutrients. The University of Maryland Medical Center states that flaxseed oil deteriorates due to the effects of heat, light and oxygen. Extraction methods that involve minimal heat and avoid exposure to light and oxygen create the highest quality flaxseed oil products.
Due to its tendency to deteriorate when heated, flaxseed oil is best used in recipes that do not require heat, such as salad dressings, or in toppings drizzled over cooked foods. Flaxseed oil should be packaged in dark containers and stored in a refrigerator to preserve its nutritional quality and taste.