What Is Cold-Pressed Olive Oil?

Over its more than 6,000-year history, olive oil has earned a variety of labels and designations. A quick walk down the olive oil aisle of a grocery store will introduce you to rows of mostly dark green and yellow bottles, some with names in different languages, all displaying identifications like "refined" or "unrefined" and "virgin" or "extra-virgin" — you need a guide to buying olive oil just to navigate the shelves. Many of those labels are closely regulated, with specific chemical compositions and processes required to merit their display. For example, according to regulations from the USDA, U.S. extra-virgin olive oil has to meet specific purity and quality criteria. Cold-pressed, on the other hand, is not quite as closely controlled.

Over the years, the European Union has set down some standards for the terms "first cold-pressed" and "cold-extracted," but the labels are mostly unregulated in the U.S. Even in Europe, the standards are simple compared to the requirements around the extra-virgin moniker. In a basic way, cold-pressing labels virgin or extra-virgin olive oils that are extracted at a temperature that never exceeds 27 degrees Celsius, or 80.6 degrees Fahrenheit.

For that standard to make sense, it helps to know how olive oil is made. Olive oil is produced by harvesting the olive fruit from olive trees and milling it to create an olive paste. Until the mid-1900s, the next step would be to use a stone or hydraulic press to get the oil out. In modern times, malaxation (a kind of massaging) and a centrifuge are more common. Sometimes, heat is used to aid in the extraction process. More oil can be extracted when heat is applied, but the properties of the oil are also changed — heat removes nutrients and impacts the quality, taste, and color.

When the olives are cold-pressed, though, the temperature is closely watched so that the olive oil doesn't face any adverse effects. In theory, everything stays below that 27 degrees Celsius mark, and no additional chemicals are added. Although much extra-virgin olive oil is cold-pressed, it doesn't have to be. The product can maintain extra-virgin status above the temperature limit, because the required taste, aroma, and chemical composition can still be present. However, extra-virgin that isn't cold-pressed will have a lower concentration of the antioxidant polyphenols, making cold-pressed extra-virgin the highest quality of the olive oils.

If you're outside the E.U., the cold-pressed label might not mean much and can just be used for marketing. Since the proof  is in the high level of polyphenols, you can request a phenolic analysis from the company to ensure what you're getting is actually nutrient-rich, cold-pressed extra virgin. If you're reading this while standing in the olive oil aisle of the grocery store, that route might be less than practical. Instead, you can look for a few immediate indicators of quality.

The first is the bottle itself. Heat and light will degrade olive oil and remove its nutrients; you want a bottle that's dark glass or metal to protect the product from the elements. The next indicator of quality is the harvest date. You're likely familiar with a "best before" date, which is two years from bottling. With olive oil, the harvest date also matters. Not every manufacturer will include it, but this date is when the olives were taken from the tree and started their processing, and it can help you tell if your olive oil is still fresh — find a harvest date that's less than a year ago. Single-origin olive oil is also preferable over an oil that lists more than one country of origin. And, even though cold-pressed isn't a regulated term in the U.S., there are still regulatory agencies that monitor olive oil quality, so look for certifications indicating that the olive oil has been tested for defects.