1. Expiration date

If the bottle does not have an expiration date do not buy it. And better yet, it should have a harvest date. The reason for this is not that olive oil will go bad in the sense that perishable foods go bad, but that it is old. In my previous post I noted that old olive oil does not taste good and it does not have the health benefits of the fresh olive oil. 

The older the olive oil the less polyphenols it will have. You should look for an expiration date that is about a year and a half away. If you find that, then that means it has been harvested in the previous year.

Usually the expiration date is about 1 ½ -2 years after harvest date. But that does not mean that you should be using it until that date.

Ideally, and if you want to replicate what was being done in the traditional Mediterranean diet, you want to consume olive oil within 1 year of it’s harvest date. In other words use olive oil of that year’s harvest. 

Generally though you should use an open bottle of olive oil in a short period of time.

2. Harvest date

As I have mentioned before, the benefits of olive oil come mainly from the polyphenols and the content of polyphenols is dependent on a few factors and one of them is when the olives are harvested. 

Early harvest when the olives are partially green results in an olive oil that has a higher polyphenol content, and that also means a longer shelf life. 

These olive oils have a more herby and bitter taste. Olive oil from late harvest (mature olives) has a more buttery taste, but less polyphenols (antioxidants) and shorter shelf life, in other words it has a quicker loss of its nutritional benefits. So if possible pick a harvest date that that is ideally November or even late October as its harvest date.

3. Variety of olive

Yes this is important and more and more producers include the variety of olive they are using on the bottle, the same way wine bottles have the variety of grape. But why is the olive variety important? Well, it tells you a lot. First of all some olive varieties have a very high polyphenol content and that is a good thing as we know.

Olive varieties with high polyphenol content also produce olive oil that is more stable, that means longer shelf life and slower loss of nutrients compared with olive varieties with medium or low polyphenol content.

• Very High Polyphenol Content: Coratina, Conicabra, Koroneiki, Moraiolo, Picual
• High: Bosana, Chemlali, Manzanillo, Picholine
• Medium: Arbosana, Barnea, Empeltre, Frantoio, Hojiblanca, Leccino,
• Low: Arbequina, Picudo, Taggiasca

Source: International Olive Oil Council

*Keep in mind that many producers/bottlers, particularly larger ones combine different varieties of olive to produce a specific flavor profile.

4. Bottle

Avoid bottles in clear glass as light can affect the oil. Bottles that are made of dark glass are better or not clear at all is even better. Do not be influenced by the shape and design of the bottle either. Many producers feel that good olive oil deserves a state of the art bottle.

Sure, but those bottles and designs cost the producers a lot and as a result you are paying more for that olive oil because of the bottle and design. Having said that, some of the best olive oils come in very simple bottles.

5. Olive oil grade

The majority of olive oil you consume should be mostly Extra Virgin Olive Oil. A new report from the U.S. International Trade Commission showed that U.S. consumers are generally unfamiliar with the range of olive oil grades. So before I explain why you should only use extra virgin olive oil let’s just go over the different grades. The International Olive Oil Council has established the following categories-I have added the corresponding U.S. title:

a. Extra virgin olive oil (In the U.S: US Extra Virgin Olive Oil): virgin olive oil, which has a free acidity of not more than 0.8 grams per 100 grams.

b. Virgin olive oil (US Virgin Olive Oil): virgin olive oil, which has a free acidity of not more than 2 grams per 100 grams.

c. Refined olive oil (US Refined Olive Oil) is the olive oil obtained from virgin olive oils by refining methods, which do not lead to alterations in the initial glyceridic structure. It has a free acidity of not more than 0.3 grams per 100 grams. It is basically low quality olive oil that is refined physically and chemically to remove undesirable qualities such a free fatty acids and unpleasant flavor and odor.

d. Olive oil (in the US: US Olive Oil) is the oil consisting of a blend of refined olive oil and virgin olive oils fit for consumption as they are. It has a free acidity of not more than 1 gram per 100 grams.

e. Olive-pomace oil is the oil obtained by treating olive pomace with solvents or other physical treatments. It is blended with virgin olive oils and is fit for consumption as they are. It has a free acidity of not more than 1 gram per 100 grams.

Please look at these titles carefully, I noted the most common you may see at the store. Look at “d.” it says Olive Oil. One would think that olive oil is olive oil, but in fact it is virgin olive oil mixed with refined olive oil, yes the one that has been chemically processed and contains little to no antioxidants.

To Sum It Up

Basically you should focus on consuming extra virgin olive oil. Most studies showing benefits of olive oil are referring to extra virgin olive oil, all those other olive oils do not have those benefits, apart from being a source of monounsaturated fats.

I also read often that you should use lower grade olive oil for frying due to smoke point. I have talked about this in the past, and it is important to know that in fact extra virgin olive oil has a high smoke point and is more stable then other categories. So unless you plan to deep-fry (which is not something you should do often anyway) extra virgin olive oil is the way to go.

How to get started?

By the way if you like this and want to get started in the Mediterranean diet

You might like this 28-Day Action Mediterranean Diet Program to give you a no brainer easy approach that gets you started with shopping lists, quick and easy recipes, immunity boosting foods, and tips for creating Mediterranean meals.

Click here or the link below