How to Choose Olive Oil

Faced with dozens of bottles lined up on the shelf, choosing a quality olive oil can feel daunting. Labels compete with claims — "extra virgin", "first cold press", "product of Italy" — without consumers always knowing what they truly mean. Yet the difference between an excellent extra virgin olive oil and a mediocre product is considerable, both in terms of flavour and nutrition. This comprehensive guide gives you all the keys to making the right choice, whether you are buying from a supermarket, a speciality shop or directly from a producer.

Why Your Choice of Olive Oil Matters

Not all olive oils are created equal. A genuine quality extra virgin olive oil contains between 200 and 800 mg of polyphenols per kilogram — the bioactive compounds responsible for its health benefits. A low-quality oil, even one labelled "extra virgin", may contain only a fraction of that. On the flavour front, the difference is equally stark: where a quality oil delivers a complex fruitiness with notes of fresh grass, almond and tomato, a mediocre one will taste bland or even present defects (rancid, musty, vinegary).

The global olive oil market is unfortunately prone to misleading practices. Journalistic investigations and university studies have revealed that up to 70% of oils labelled "extra virgin" sold in certain countries fail to meet the chemical and sensory criteria of that category. Knowing how to read a label and understanding what sets a quality oil apart is therefore an essential skill for any informed consumer.

Reading the Label: Key Information

The label on a bottle of olive oil contains (or should contain) several essential pieces of information. Here is what to look for first.

The Category

The designation "extra virgin olive oil" is the highest quality category. It guarantees exclusively mechanical extraction, a free acidity below 0.8% and the absence of any organoleptic defects detected by a certified tasting panel. If the label simply reads "olive oil" without the qualifier "extra virgin" or "virgin", the product is a blend containing refined oil. For a detailed breakdown of these categories, see our guide on olive oil types and quality.

Acidity

Free acidity, expressed as a percentage of oleic acid, indicates the quality of the raw material and the care taken during processing. The regulatory threshold for extra virgin is 0.8%, but the finest oils display an acidity below 0.3% or even 0.2%, like our Alentejo oil. A low acidity means the olives were healthy, harvested at the right stage of ripeness and processed promptly after picking.

Origin

EU regulations require the origin of olive oil to be stated. Be wary of vague wording such as "blend of olive oils originating in the European Union": this indicates a mix from various sources, often synonymous with average quality. Favour oils that name a specific country and, better still, a specific region. Renowned terroirs — the Alentejo in Portugal, Crete in Greece, Jaén in Spain, Tuscany in Italy — offer distinctive aromatic profiles linked to their local varieties and climate.

Harvest Date and Best-Before Date

The harvest date (or "campaign") is a valuable piece of information that serious producers include on the label. Unlike wine, olive oil does not improve with age: it is at its best within 12 to 18 months of harvest. The best-before date is usually set at 18 or 24 months after bottling. Always choose the most recent harvest available.

Extraction Method

The wording "cold-extracted" or "cold-pressed" guarantees that the temperature did not exceed 27 °C during extraction. This is a regulatory requirement for the "extra virgin" designation, but its explicit mention on the label signals a producer committed to transparency. Hot processes degrade polyphenols and volatile aromas, resulting in an oil that is poorer on every measure.

Understanding Olive Oil Categories

The International Olive Council (IOC) defines several olive oil categories, but three are primarily available to consumers:

• Extra virgin: the highest category. Mechanical extraction only, acidity ≤ 0.8%, zero organoleptic defects, presence of fruitiness. It is the only category that retains the full complement of polyphenols and aromas.
• Virgin: same extraction process, but acidity can reach 2% and minor organoleptic defects are tolerated. Decent quality but inferior to extra virgin.
• Olive oil (without further qualifier): a blend of refined oil (chemically treated to remove defects, odour and taste) and a small proportion of virgin oil added to provide minimal flavour. Very low in polyphenols.

For a comprehensive guide to these categories, their criteria and associated labels, see our article on olive oil types and quality.

The Importance of Origin and Terroir

As with wine, terroir profoundly influences the character of an olive oil. Climate, soil, altitude, the varieties grown and farming practices all create unique aromatic profiles. Oils from southern Spain (Picual) tend to be robust and bitter; those from Tuscany (Frantoio, Moraiolo) are herbaceous and peppery; oils from Crete (Koroneiki) are fruity and mild; those from the Portuguese Alentejo (Cobrançosa, Cordovil) offer notes of fresh grass, olive leaf, green apple and aromatic herbs.

Single-variety oils (monovarietal) allow you to fully appreciate the expression of a terroir. Blends, on the other hand, seek complexity and balance by combining the characteristics of several varieties. Neither approach is inherently superior: everything depends on the producer's expertise.

Labels and Certifications: Finding Your Way

PDO / DOP (Protected Designation of Origin)

This European label guarantees that the oil is produced, processed and packaged within a defined geographical area, according to a strict set of specifications. It is one of the most reliable marks of quality. There are over 130 PDOs for olive oil in Europe, covering Spain, Italy, Greece, Portugal and France.

PGI (Protected Geographical Indication)

Less restrictive than PDO, the PGI requires that at least one stage of production takes place in the designated geographical area. It offers greater traceability than unlabelled oils, but with more flexibility than a PDO.

Organic Certification

The Organic label certifies that the olives were grown without synthetic pesticides or fertilisers. While it guarantees more environmentally responsible farming practices, it does not in itself guarantee superior flavour quality. A carefully produced conventional oil can be gustatively superior to a poorly made organic one. Ideally, look for an oil that combines Organic with PDO/DOP.

Awards and Competitions

Medals from recognised international competitions (the IOC's Mario Solinas Award, NYIOOC, Olive Japan, BIOL for organic oils) provide objective validation of organoleptic quality. Check that the medal corresponds to the current harvest and not a previous year.

Price vs. Quality: What Justifies the Cost

The price of a quality extra virgin olive oil is significantly higher than that of a standard oil, and this is explained by concrete factors:

• Harvesting: early picking (green or turning olives) produces oil richer in polyphenols but with a lower yield — it takes 5 to 8 kg of olives to produce one litre of quality oil, compared with 3 to 4 kg for a late harvest.
• Speed of processing: the best oils are pressed within hours of harvest, which demands a rigorous and costly logistical organisation.
• Storage: stainless steel tanks under controlled atmosphere (nitrogen) preserve the oil's qualities but represent a significant investment.
• Packaging: dark glass bottles or metal containers protect the oil from light but cost more than clear plastic.

As a general rule, a genuine quality extra virgin olive oil costs at least 10 to 15 euros per litre in Europe. Below 7 euros per litre, it is virtually impossible to produce an oil that truly meets extra virgin standards. Consider this cost an investment in your health and culinary enjoyment — two tablespoons a day amount to just 20 to 30 cents for a superior-quality oil.

Choosing by Use: Raw or Cooking

The intended use of your olive oil influences the optimal choice. For a detailed guide to cooking, see our article on cooking with olive oil.

Raw Use (dressing, finishing)

This is the use that best showcases an oil's quality. Choose a premium extra virgin with intense fruitiness and good aromatic complexity. Single-variety oils or early-harvest oils are ideal drizzled over a salad, grilled fish, soup or fresh bread. It is also when consumed raw that polyphenols are best preserved.

Cooking Use

Extra virgin olive oil can withstand cooking up to 180-190 °C (its smoke point ranges between 190 and 210 °C depending on quality). For sautéing and oven cooking, a mid-range extra virgin with medium fruitiness is an excellent choice: it provides nutritional benefits without the heat wasting the finest aromas. Avoid prolonged deep-frying, however, as it rapidly degrades fragile compounds.

One Oil for Every Occasion

Knowledgeable enthusiasts often keep two oils in their kitchen: a premium oil for raw uses and a good-quality extra virgin for everyday cooking. This approach lets you enjoy the best of each oil without straining the budget.

How to Taste before Buying

If you have the opportunity, taste before you buy. It is the most reliable way to assess an oil's quality. Food fairs, farmers' markets and speciality shops often offer tastings. Here are the three criteria to evaluate, used by the International Olive Council's professional tasters:

• Fruitiness: bring the oil to your nose in a warmed glass. You should detect aromas of fresh olive, possibly accompanied by notes of grass, green tomato, almond, apple or artichoke. The absence of fruitiness is a defect.
• Bitterness: on the palate, the oil should display a pleasant bitterness, a sign of the presence of oleuropein and its derivatives. Zero bitterness indicates an oil depleted of polyphenols.
• Pungency: on swallowing, you should feel a peppery sting at the back of the throat, sometimes quite sharp. This is the signature of oleocanthal, olive oil's natural anti-inflammatory. The more intense the pungency, the richer the oil in oleocanthal.

An oil that displays all three attributes in harmony is a quality oil. To explore this subject further, see our comprehensive guide on how to taste olive oil.

Storage after Purchase

Once you have chosen your oil, proper storage is essential to preserve its qualities. The three enemies of olive oil are light, heat and air. Store it in a cool place (14-18 °C ideally), away from direct light, and always reseal the bottle carefully after each use. Avoid storing it next to the cooker or near a sun-facing window.

The container also plays an important role. Dark glass bottles, metal tins and bag-in-box formats offer superior protection compared with clear bottles. For a detailed guide including shelf-life, signs of rancidity and professional tips, see our article on how to store olive oil.

Our Recommendation

At Domaine Boeglin, we produce an extra virgin olive oil from Cobrançosa (80%) and Cordovil (20%) varieties, grown in the Alentejo region of Portugal. Our olives are harvested at the optimal stage of ripeness (turning) and cold-pressed on the same day as the harvest, ensuring an exceptionally low acidity (≤ 0.2%) and maximum polyphenol richness.

The result is an oil with medium to intense fruitiness, featuring characteristic notes of fresh grass, olive leaf, green apple and aromatic herbs. Its balanced bitterness and pungency testify to its high bioactive compound content. It is ideal both for dressing and for gentle cooking.

Discover our extra virgin olive oil from the Alentejo and experience an exceptional oil produced with passion and exacting standards.

"Choosing your olive oil is like choosing your wine: you need to care about the terroir, the producer and the product. Quality comes at a price, but the rewards — in flavour and in health — are priceless."