A long-time staple and essential ingredient of Mediterranean cuisine, olive oil is becoming increasingly popular all over the world.

Believed to be the healthiest of plant-based oils, olive oil is high in polyphenols, powerful antioxidants which can prevent disease, and ‘good’ monounsaturated fats which are also beneficial to health.

Good-quality olive oil also has a divine taste, adding flavour and enhancing any preparations it’s added to.

But with so many olive oils on the market, how to know which one to choose? Here are some helpful pointers:

1. Only buy extra virgin olive oil.

Extra virgin olive oil is the highest grade of olive oil. It is cold extracted through pressing and grinding, and produced without the use of chemical or industrial refining processes, or excessive heat. This is the highest quality olive oil; all other types are made using industrial and chemical processes which cause the oil to lose its nutritional properties and flavour. To qualify as an extra virgin olive oil, the acidity level of the oil can not be more than 0.8 percent per 100 grams.

An olive oil which is labeled as ‘virgin’ or ‘light olive oil’ is also cold-pressed but it has been refined in some way, making it a lower grade oil with a higher acidity level: between 1 and 3.3 percent. ‘Pomace oil’ is produced with what is leftover after the first pressing and is highly refined using solvents.

ALEA olive oil, Salento, Italy

2. Check the label.

Check to see if the olive oil has a ‘protected denomination of origin’ designation which is an assurance that the product was produced, processed and prepared in a specific geographical region. Olive oils with such designations are more likely to be of a high quality. On Italian olive oils this designation will appear as ‘DOP’, while in Spain it would be ‘DO’, and ‘PDO’ in Greece. If the oil is organic, this increases the likeliness that it’s a high quality oil.

3. Look at the date of production.

Oil is best when it’s consumed as soon as possible after production. It then quickly loses its taste and quality within only a few months. Unlike wine which matures and improves with age, olive oil is more like a freshly-pressed fruit juice which loses its flavour and aroma quickly. Check to see if there’s a date of production on the bottle, though this is not very common. ‘Best by’ dates are usually a period of two years from the date the oil was bottled. So if the date on the bottle is in two years time, it’s more likely to be fresh. However, olive oil in many countries is often stored for years before being bottled so this is not a guaranteed way to determine its freshness.

Venta del Baron, Mueloliva, Spain

4. What does the price tag say?

Good quality olive oil is not cheap. Producing authentic extra virgin olive oil is an expensive process and the price tag will reflect this. Low priced oils are bound to be of inferior quality and produced through industrial and / or chemical processes. Not a good deal at all!

5. Check for sediment.

Check for any sediment at the bottom of the bottle. Sediment or deposits can cause the oil to spoil faster and quickly lose its taste and quality.

6. What’s the colour?

As for the colour of the oil itself, this does not influence quality. This is why professional olive oil tasters use coloured tasting glasses so that they’re not influenced by the colour of the oil when grading it. However, cloudiness or murkiness are signs of a good quality oil.

Olive oil should be protected from heat and light, which cause it to lose its properties and taste faster. For this reason, olive oil should only be stored in dark glass bottles. At home, keep olive oil in a cool and dark place and not on an open shelf.

Ancient olive trees in Puglia, Italy

7. Smell it and taste it.

Olive oil shops and bars are becoming increasingly popular in cities across the world. These specialised olive oil retail outlets offer customers the possibility to taste a variety of oils before making a purchase. This is definitely an advantage as you can choose the oil you like the taste and smell of, and well-informed staff should be able to answer any questions about how the oil was made and where it originates from. Before tasting, make sure you smell the oil: a high-quality olive oil will have an intense aroma. Good quality extra virgin olive oils will have a marked fruity flavour. Also, though many consumers do not appreciate bitterness in an olive oil, this is considered to be a highly desirable quality and is an indicator of a high level of polyphenols, and a high quality oil.

Gallo Olive Oil, Portugal

By Isabel Putinja, Travel Writer