Guides & Advice

Everything you need to know about olive oil

Written by Tom | 22nd July 2020

Few foodstuffs can compete with olive oil in popularity and versatility. Ranging from smooth dressings to recipe essential, this Mediterranean mainstay is used throughout the entire cooking world. Yet for something so pervasive in our food, it's an ingredient that many know little about. With the help of olive oil seller Stefano Sattin and expert Andrea Curatolo, we've put together a guide on everything you need to know about this golden oil. 

What should 'good' olive oil taste like?


As extra virgin olive oil is the juice deriving directly (and exclusively) from olives, its taste should always be close to that of the fruit it's squeezed from. The flavor then will depend on the type of olives used, the time of harvest and how ripe the olive is. If we were to generalize, we could say that good olive oil should always have a nice “green” smell and taste. Sometimes it's reminiscent of the smell of freshly cut grass and sometimes it has a stronger green taste and smell, similar to that of leaves. Fun fact - the riper the olive, the more the oil will taste like almonds. 

The best kind of olive oil comes from freshly squeezed olives

Does age (like wine) have any influence?

The age of olive oil is inversely proportional to its quality. The best kind of olive oil is the one that has just been “crushed”, meaning it has been freshly squeezed from olives. The more an oil ages, the lower the quality. It's recommended that any stored olive oil should be finished before the start of the new production round, which takes place in between the months of October and November every year. 

What are some indicators of a good olive oil?


The main indicators for a good olive oil are the following:

    - The olives should be harvested when still green or when they start changing color (from green to red). A black olive can produce big quantities of oil but its quality is low.

    - The olives should be taken to the oil mill and pressed within 24 to 36 hours from the time of harvest.

    - The oil should be prepared with a cold olive-press system, meaning below 27 degrees celsius.

The greener the olive, the higher the quality of oil it will be produce

Can you explain the difference between extra virgin and normal olive oil?

On a product level there are four categories of edible olive oil:

    -  Extra virgin olive oil: oil that is pressed directly from olives in line with the EU law quality standards.

    - Virgin olive oil: olive oil that has lower quality standard than the ones established by regulations.

    - Olive oil: it is obtained from a mix of different olive oils, some of which are refined through chemical procedures

    - Olive pomace oil: this oil is obtained from the production scraps of extra virgin olive oil.

Extra virgin olive oil is therefore the highest quality of olive oil that can be found on the market, all other types of olive oil are of lower quality and are created for low price mass distribution.

Is the color of the oil important?

During the organoleptic analysis of olive oil (a type of taste test completed by a panel of experts), visual analysis is not included and in fact, olive oil is served in cobalt blue glass to prevent any visual stimuli from influencing the analysis. Extra virgin olive oil can be of different colors: deep green, grass green, or gold yellow, but the color has no influence on the quality. 

Olive oil color can range from deep greens to golden yellows, but has no bearing on the quality

What about the bottle itself?


The biggest enemy of olive oil is air - oxidation must be avoided - and the second biggest threat would be light. As a result, it's best to store the olive oil in a bottle that can protect it from light: dark colored glass, ceramic or a tin-plated can will do. There are also transparent bottles with special glass protecting against UV rays. Such special bottles are very expensive and feature exquisite packaging, designed for exclusive and private gifts, and cannot be found in restaurants. 

How should olive oil be stored?


Extra virgin olive oil in dark glass bottles should be stored in environments where the temperature does not go below eight degrees or above 30 degrees. At eight degrees, the oil starts to freeze and turns from liquid to solid. Once the oil turns back to liquid as temperatures rise, there will not be a change in taste and aroma but rather a structural change. The oil will be less fat and more liquid, hence more watery. This harms the quality of the oil - vegetable fats should feel viscous in the mouth if they're good quality.

When olives are harvested, they shouldn't be stored in crates with a big capacity. When olives are piled in big crates, the excessive weight will cause the lowest layer of olives to get crushed. The crushed olives will then start to oxidise and damage the quality of the oil. And to reiterate - olives should always be pressed as soon as possible after harvest. 


Get acquainted with some quality olive oil in our weekly auctions or  register as a seller  with Catawiki. 

Discover more  oil & vinegar | wine

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