If you shop at Costco and use a fair amount of olive oil, you have probably picked up the Kirkland Signature Extra Virgin Olive Oil.  Or at least considered it.  But did you ever wonder how it stacks up against other extra virgin olive oils that are on the market?  And what is so special about extra virgin olive oil anyway?  Recently, results from a UC Davis study were released regarding the standards of extra virgin olive oils that are on the market in the US.  After looking at the results, it’s clear that the Kirkland Signature extra virgin olive oil is not only a great bargain price-wise, but is also some of the best quality olive oil on the market in the US.

But before I get to the exciting bit, I’ll fill you in on a bit of olive oil information.  Currently, the US is the third largest market for olive oil with Americans consuming more than 75 million gallons last year.  That figure represents a doubling in US consumption over the last decade.  As a result of this growing level of consumption, I’m sure, the USDA has decided that it is time to start getting a little more structured about what can be sold as ‘extra virgin’ vs. ‘virgin’ olive oil.  So, starting in the fall, the USDA will roll out new, voluntary, labeling standards for olive oils sold in the US.  This is great for consumers because it means that companies will have to start being more up front about the acidity levels of their oils, as well as the process they used to extract the oil from the olives.  More knowledge about what you’re eating is always good, right?

So, for all of us that are wondering, the different classifications of oil are based on the production method, acidity levels, and the taste.  The less mechanical or chemical intervention, as well as the lower the acidity level, the better the quality of the oil.  Here’s a how the IOOC (the International Olive Oil Council, not something the US belongs to for some reason, but governs the standards for the rest of the world) quality standards for retail olive oil labels, and most likely what you’ll see in the stores:

• Extra-virgin olive oil comes from virgin oil production only, contains no more than 0.8% acidity, and is judged to have a superior taste. Extra Virgin olive oil accounts for less than 10% of oil in many producing countries. It is used on salads, added at the table to soups and stews and for dipping.
• Virgin olive oil comes from virgin oil production only, has an acidity less than 2%, and is judged to have a good taste.
• Pure olive oil. Oils labeled as Pure olive oil or Olive oil are usually a blend of refined and virgin production oil.
• Olive oil is a blend of virgin and refined production oil, of no more than 1.5% acidity. It commonly lacks a strong flavor.
• Olive pomace oil is refined pomace olive oil often blended with some virgin oil. It is fit for consumption, but may not be described simply asolive oil. It has a more neutral flavor than pure or virgin olive oil, making it unfashionable among connoisseurs; however, it has the same fat composition as regular olive oil, rendering it the same health benefits. It also has a high smoke point, and thus is widely used in restauraunts as well as home cooking in some countries.
• Lampante oil is olive oil not suitable as food; lampante comes from olive oil’s long-standing use in oil-burning lamps. Lampante oil is mostly used in the industrial market.
• Refined olive oil is the olive oil obtained from virgin olive oils by refining methods that do not lead to alterations in the initial glyceridic structure. It has a free acidity, expressed as oleic acid, of not more than 0.3 grams per 100 grams (0.3%) and its other characteristics correspond to those fixed for this category in this standard. This is obtained by refining virgin olive oils with a high acidity level and/or organoleptic defects that are eliminated after refining. Over 50% of the oil produced in the Mediterranean area is of such poor quality that it must be refined to produce an edible product. Note that no solvents have been used to extract the oil, but it has been refined with the use of charcoal and other chemical and physical filters. An obsolete equivalent is “pure olive oil”.

So, now that you know all that, we can finally get down to the test results from the UC Davis testing.  The team from UCD tested 19 different brands: 14 imported and five California made.  All bottles were purchased in March at supermarkets or big box stores in Sacramento, San Francisco and Los Angeles counties. Testing was conducted on three bottles of each brand from each location.  The team worked with Australian olive experts and used international standards for evaluating extra virgin olive oil.  All of the oils were evaluated both by chemistry and a panel of trained tasters.

Of the imports, only Kirkland Signature Organic passed all the extra-virgin standards with samples from all three locations. Samples of Bertolli, Pompeian, Carapelli, Mezzetta and Mazola failed from all locations.  Of the California-made brands tested, all bottles of Corto Olive, California Olive Ranch, McEvoy Ranch Organic and Lucero met the extra-virgin criteria.   Here’s a listing of all olive oils tested and how many of their samples passed:

Kirkland Signature Olive OIl

Imported Olive Oils:

• Kirkland Signature Organic Extra Virgin Olive Oil: All samples passed.
• Great Value 100 percent Extra Virgin Olive Oil: One of three samples failed.
• Star Extra Virgin Olive Oil: One of three samples failed.
• Filippo Berio Extra Virgin Olive Oil: Two out of three samples failed.
• Colavita Extra Virgin Olive Oil: Two of three samples failed.
• Newman’s Own Organics Extra Virgin Olive Oil: Two of three samples failed.
• Rachael Ray Extra Tasty Extra Virgin Olive Oil: Two of three samples failed.
• Safeway Select Extra Virgin Olive Oil: Two of three samples failed.
• 365 Everyday Value 100 percent Italian Extra Virgin Olive Oil: Two of three samples failed.
• Bertolli Extra Virgin Olive Oil: Three of three samples failed.
• Pompeian Extra Virgin Olive Oil: Three of three samples failed.
• Carapelli Extra Virgin Olive Oil: Three of three samples failed.
• Mezzetta Extra Virgin Olive Oil: Three of three samples failed.
• Mazola Extra Virgin Olive Oil: Three of three samples failed.

Domestic Olive Oils:

• Corto Olive Extra Virgin Olive Oil: All samples passed.
• California Olive Ranch Extra Virgin Olive Oil: All samples passed.
• McEvoy Ranch Organic Extra Virgin Olive Oil: All samples passed.
• Lucero (Ascolano) Extra Virgin Olive Oil: All samples passed.
• Bariani Olive Oil Extra Virgin Olive Oil: One of two samples failed.

The UCD research team found that 69 percent of the imported oils sampled failed to meet internationally accepted standards for extra virgin olive oil. By comparison, only 10 percent of the California-produced oils in the test failed to meet those standards.  And again, I’ll reiterate that of the imported olive oils, only the Kirkland Signature Organic had all of its samples pass the tests.  The reasons that the oils might not have met the extra-virgin standards are due to oxidation, adulteration with cheaper refined olive oil or poor-quality oils made from damaged and overripe olives, processing flaws or improper oil storage.

So, the result of this is that if you are going to buy an imported extra virgin olive oil, you really should be shopping at Costco and buying the Kirkland Signature brand.  Otherwise, you’re just not getting the best quality you could (and you’re probably paying too much to boot).

For more information, use the following links:

• The Sacramento Bee: UCD tests ‘extra virgin’ olive oil claims
• Wikipedia: Olive Oil
• The Costco Connection: Costco Brings “Made in Italy” to Your Table