Most Commonly Asked Questions About Olive Oil
(Excerpted from Colavita USA’s popular cookbooklet, Cooking With Olive Oil American Style!)
The olive mash is then spread onto thin mats. These mats are stacked, and placed into a machine “press.” As the press applies several hundred pounds of pressure, oil and water from the mash seep out of the mats, and drip into collection vats. In the traditional method, no heat is applied in the pressing–hence the term “first cold pressed.” The oil is allowed to settle, and any vegetable water is removed either by centrifuge or decantation.
Oil extracted from the mechanical pressing of the olive is described as “virgin” olive oil, because it is pure, unrefined and unprocessed.
Olive Oil. Ordinary “olive oil” is actually a blended oil product. Olive oil producers start with low quality virgin olive oils. For these oils to be fit for consumption, they must be refined using mechanical, thermal and/or chemical processes. The resulting “refined olive oil” is largely colorless and tasteless. Before the resulting product is sold as “olive oil,” the producer blends into the refined olive oil a percentage of quality virgin olive oil to provide color and taste.
“Light” or “Mild” Olive Oil. Light olive oil is a variation on ordinary olive oil. Producers of this product use a highly refined olive oil, and add less quality virgin oil than that typically used to blend olive oil. The only thing “light” about light olive oil is the taste and color; it has the same caloric and fat content as other oils.
Olive-Pomace Oil. Olive-pomace oil is the residue oil that is extracted by chemical solvents from previously pressed olive mash. This oil must be highly-refined to remove chemical impurities. Like ordinary olive oil, refined olive-pomace oil is enriched with virgin olive oil prior to sale.
Olive Oil Blends. Olive oil blends (e.g., canola oil enriched with some virgin olive oil) are sometimes used as a more economical substitute for olive oil (but not as a substitute for extra virgin olive oil). Because the production of good olive oil is labor intensive–the olives must essentially be picked by hand–the resulting product is more expensive than other vegetable oils. To offer a more economical product with some of the goodness of olive oil, some companies make olive oil blends. In an olive oil blend, the producer uses a base of a less expensive vegetable oil (e.g. canola oil) to which it adds a percentage (e.g. 25%) of virgin olive oil. These products have proven particularly attractive to restaurant and institutional purchasers where the small savings per tablespoon results in big savings due to the large volume they purchase.
Taste is the most obvious difference between olive oil and the commercially popular vegetable oils such as corn, soybean and canola oils. These oils are tasteless fats. You would not want to eat a piece of bread dipped in vegetable oil; for the same basic reason, many chefs refrain from adding tasteless fat to the foods they prepare. When you cook with oil, get the most flavor and texture you can.
Olive oil, especially extra virgin olive oil, adds a flavor and textural dimension lacking in other oils, making it a suitable substitute for butter and margarine in almost any recipe. In fact, more and more restaurants are serving extra virgin olive oil, both plain or flavored with salt and pepper, as an alternative to butter for bread.
Nutritionally, olive oil contains more monounsaturated fat than any of the popular vegetable oils. For more information on the nutritional qualities of olive oil versus other oils and fats, please refer to the last chapter in this booklet.
Moreover, vegetable oils are industrial, processed foods. Vegetable oils are generally extracted by means of petroleum-based chemical solvents, and then must be highly refined to remove impurities. Along with the impurities, refining removes taste, color and nutrients.
Extra virgin olive oils are not processed or refined. It is said that you do not make extra virgin olive oil, you find it. Extra virgin olive oil is essentially “fresh squeezed” from the fruit of the olive tree, without alteration of the color, taste, and nutrients or vitamins. Because of the integrity of the product, and its antioxidant components, olive oil will keep longer than all other vegetable oils.
Saturated fat and cholesterol have been linked to increased levels of low density lipoproteins (LDLs)–the “bad cholesterol.” Thus, compared to butter, a serving of olive oil contains much less saturated fat (only 2 grams) and no cholesterol. The comparison with margarine is more difficult because the fat breakdown in margarines varies by manufacturer and ingredient. Margarine typically contains approximately 10 grams of fat per tablespoon. However, to solidify the vegetable oils used to make margarine, the oils have to be hydrogenized. In the hydrogenization process, trans fatty acids are created. Trans fatty acids have a double whammy effect of increasing LDLs and lowering the high density lipoproteins (HDLs)–the “good cholesterol” (see discussion of health issues in last chapter of this booklet).