Olive oil is simply the juice that comes from an olive. The olive is a fruit, grown on the olive tree. Want to know more than that? The answer to exactly how olive oil is made will depend solely on the type of olive oil, or grade, that it is.
We are going to do a fairly basic review of the grades of olive oil and how they are made. There are many ways you can learn these things whether they are visual slideshows, videos, or reading.
For an easy step-by-step review on how olive oil is made we recommend watching the slide share presentation below:
How Each Grade Of Olive Oil Is Made
If you prefer to read articles, below you will find a review of the different olive oil grades, how they are made and what makes them different from one another. You can also download the information in a PDF form at the bottom of this page.
Extra Virgin Olive Oil
Extra Virgin is the highest grade of olive oil available in both organic and traditional varieties. First, the olives are harvested and washed with cold water. They are then ground into a paste and spun in a centrifuge to extract this high-quality oil. Typically this process occurs within 24 hours of picking the olives from the trees.
Extra Virgin is known as the "first, cold-press", though it's actually spun instead of pressed in a modern system. It is technically an olive fruit juice because it's simply the liquid extracted from the fruit of the olive. To be considered Extra Virgin Olive Oil it must have an acidity level lower than 0.8 and zero taste flaws, along with a number of other chemical requirements to have it meet the grade.
If you are interested in seeing more on how this oil is made, you can watch this explanatory video from National Geographic.
Virgin Olive Oil
Virgin olive oil is processed very similarly to Extra Virgin. The thing that makes Virgin and Extra Virgin different is the acidity level after pressing. Virgin has a max acidity level of 2.0% while Extra Virgin must be below 0.8%.
The difference in acidity level is caused by the olives themselves or the time delay between harvest and production. After the olives are harvested and are waiting to be pressed, the fruit continues to be affected by its natural environment. For example, some olives may remain in the field longer, some may be slightly riper or have more sun exposure. Each of these natural elements causes them to oxidize faster, which increases the acidity level.
Refined Olive Oil
Refined Olive Oil is Virgin Olive Oil that has been refined using a high heat process to create a mild light-tasting and more stable oil. The refining process also removes a number of the health benefits that Extra Virgin Olive Oil offers (though this is debated). Refining olive oil also provides a lower acidity level.
Refined Olive Oil is also known as Light Olive Oil or Extra Light Tasting Olive Oil on retail shelves.
Olive Oil (Pure Olive Oil)
This grade of olive oil is commonly known as Pure Olive Oil in the US bulk and retail markets. By definition, this grade is comprised of Refined Olive oil blended with Extra Virgin or Virgin Olive Oil in any ratio (though ratio blends from 70/30 to 99/1 are quite common). The ratios are determined by the supplier/manufacturer and can account for some of the price differences in Pure Olive Oil across the market. This oil has a milder taste and color than Extra Virgin or Virgin Olive Oil, though slightly more taste and color than 100% Refined Olive Oil.
Olive Pomace Oil
Olive Pomace Oil is an oil that is extracted from the pomace of the olive. Pomace is the pulp made from the pit of the olive that has already been squeezed from the olive fruit. When an olive is picked, it is ground into a paste which is squeezed or spun to get the initial oil out. The dry pulp left-over is called the olive pomace.
A solvent (typically hexane) is added to the pomace to extract any remaining oil. The solvent is removed, and the remaining Olive Pomace Oil is refined. This is a similar process used to make Refined Olive Oil — the primary difference between these two is the Pomace has been extracted using a solvent from the pomace of the olive, while Refined is extracted using a centrifuge with no chemicals.
Pomace is also the lowest cost grade of olive oil available.
Blends: Seed Oils and Olive Oil
Olive oil can be mixed with oils such as canola, sunflower, safflower or soybean to create a blended oil that is lower cost and has a milder taste. These blends can be made with any grade of olive oil and any type of base oil. Depending on the base oil that you choose blends can also be available in non-GMO, expeller pressed and organic varieties. Blends can be custom made with any ratio of oils, but the most common proportions are 75/25, 85/15, and 95/5.