The Complete Guide to Extra Virgin Olive Oil: What to Look For, Why It Matters & How to Choose the Best

Walk into any supermarket and you'll find shelves lined with bottles labelled "Extra Virgin Olive Oil." But here's what most people don't know: a significant proportion of olive oil sold under that label doesn't meet the standard. It's been stored too long, processed at too high a temperature, blended with lower-grade oils, or simply misrepresented. The result? A bottle that looks the part but delivers none of the flavour, nutrition, or health benefits of genuine extra virgin olive oil.

At Olives & Oils, we've spent years sourcing oils that genuinely earn that label — single-estate, cold-pressed, harvest-fresh EVOOs from producers who care as much about polyphenol content as they do about flavour. This guide exists to help you understand exactly what you're buying, what to look for, and why it matters.

What Does "Extra Virgin" Actually Mean?

Extra virgin is the highest grade of olive oil, defined by both chemistry and process:

• Acidity below 0.8% — measured as free oleic acid. Lower acidity indicates fresher, better-quality olives and careful handling. Most supermarket EVOOs sit right at or near this threshold.
• No heat or chemical extraction — EVOO must be extracted purely mechanically, at temperatures that preserve its natural compounds. "Cold-pressed" or "cold-extracted" means the process stayed below 27°C.
• No sensory defects — assessed by trained tasting panels. Genuine EVOO has positive flavour attributes (fruitiness, bitterness, pungency) and zero defects like rancidity or mustiness.

Virgin and pure olive oils are lower grades, often refined using heat or chemicals to remove defects — stripping out much of the flavour and nutrition in the process. If your bottle doesn't say "extra virgin," it isn't.

What Are Polyphenols and Why Do They Matter?

Polyphenols are natural antioxidant compounds found in olive oil — and they're the single biggest differentiator between a genuinely premium EVOO and a basic one.

The European Food Safety Authority (EFSA) has approved a health claim for olive oil polyphenols: oils containing at least 5mg of hydroxytyrosol and its derivatives per 20g of oil contribute to the protection of blood lipids from oxidative stress. In plain terms, high-polyphenol olive oil has scientifically recognised cardiovascular and anti-inflammatory benefits.

What qualifies as "high polyphenol"? Generally, any oil with more than 250mg/kg of total polyphenols is considered high-polyphenol. The finest oils — harvested early, processed immediately, stored correctly — can reach 500–800mg/kg or higher.

Several factors affect polyphenol content:

• Harvest timing — early harvest (October–November in Mediterranean regions) yields higher polyphenol content. Oils from late-harvest or over-ripe olives are milder but lower in polyphenols.
• Variety — certain cultivars like Koroneiki (Greek), Picual (Spanish), and Coratina (Italian) naturally produce higher polyphenol concentrations.
• Storage — polyphenols degrade with exposure to light, heat, and oxygen. Dark glass bottles, cool storage, and consuming the oil within 12–18 months of harvest preserves them.
• Processing speed — oils milled within hours of harvest retain far more polyphenols than those processed days later.

At Olives & Oils, we prioritise high-polyphenol EVOOs and provide harvest dates and, where available, polyphenol test data for our oils.

How to Read an Olive Oil Label

Most olive oil labels tell you very little — by design. Here's what to look for and what to ignore:

• ✅ Harvest date — the most important indicator of freshness. Aim for oil harvested within the last 12–18 months. "Best before" dates alone are not enough.
• ✅ Single origin or single estate — oils from one named estate or region are traceable and typically higher quality than blends.
• ✅ Cold-pressed or cold-extracted — confirms mechanical extraction at low temperature.
• ✅ Dark glass bottle — light degrades oil quality rapidly. Avoid clear glass or plastic.
• ✅ Polyphenol content listed — a mark of a producer confident in their oil's quality.
• ✅ Acidity level stated — anything well below 0.8% (e.g. 0.2–0.3%) signals exceptional quality.
• ❌ "Packed in Italy" ≠ Italian olive oil — oil can be sourced from multiple countries and packaged in Italy. Look for origin of the olives, not the packing location.
• ❌ "Light" olive oil — this refers to colour and flavour (it's refined oil), not calorie content.

Cooking vs. Finishing: Which Oil to Use When?

One of the most persistent myths about olive oil is that you shouldn't cook with extra virgin. In fact, EVOO is an excellent cooking oil — its polyphenols and natural antioxidants make it more stable under heat than many refined oils.

The smoke point of EVOO is typically 190–210°C — well above standard sautéing and roasting temperatures. Research from the University of the Basque Country found that EVOO retained more beneficial compounds after cooking than other oils commonly considered "better" for high-heat cooking.

That said, here's a practical guide:

• Everyday cooking (sautéing, roasting up to 200°C) — a good quality EVOO works perfectly. You don't need to use your finest bottle, but it needn't be supermarket grade either.
• High-heat frying (above 200°C) — a standard EVOO or refined olive oil is a sensible choice. Save the premium stuff.
• Finishing and dressing — this is where your finest EVOOs shine. Drizzled over bruschetta, grilled fish, salads, soups, or used as a dipping oil, a high-polyphenol EVOO delivers its full flavour and nutritional impact undiminished by heat.
• Baking — EVOO works beautifully in cakes, focaccia, and bread. Milder, fruitier oils complement sweet bakes; more robust, peppery oils suit savoury breads.

Origin Guide: What Different Regions Taste Like

Olive oil, like wine, is profoundly shaped by terroir — the combination of soil, climate, altitude, and cultivar that gives each region's oil its character.

Greek (especially Peloponnese, Crete, Lesvos)
Predominantly Koroneiki cultivar. Tends to be robust, grassy, and intensely peppery — particularly early-harvest oils. Often very high in polyphenols. Greece produces some of the world's finest high-polyphenol EVOOs.

Italian (Tuscany, Puglia, Sicily, Umbria)
Extraordinary diversity of cultivars — Frantoio, Moraiolo, Coratina, Nocellara del Belice, and many more. Tuscan oils are typically herbal and peppery; Sicilian Nocellara is buttery with tomato and almond notes; Puglian Coratina is intensely bitter and peppery with very high polyphenols.

Spanish (Andalusia, Catalonia, Aragón)
Picual is Spain's dominant cultivar — producing oils with distinctive tomato leaf, green fruit, and pepper notes, with excellent stability and high polyphenol potential. Arbequina is milder, sweeter, and more delicate.

Portuguese (Alentejo, Trás-os-Montes)
Often underrated, Portuguese EVOOs — particularly from Galega and Cobrançosa cultivars — offer complex, medium-intensity flavour profiles with good polyphenol content and excellent value.

Lebanese, Turkish & emerging origins
Some of the most exciting EVOOs we source come from smaller producers in Lebanon, Turkey, and North Africa — often running small family estates with exceptional care and unique cultivars not found elsewhere.

How Olives & Oils Selects Its Oils

Every oil on our shelves has been chosen against a consistent set of criteria. We taste before we list. We check harvest dates. We prioritise producers who share their polyphenol data openly, who harvest early, and who mill within hours of picking.

We work with small estates and specialist importers who share our obsession with quality over convenience. That means our range changes seasonally as new harvests arrive — an early-harvest Greek Koroneiki from October won't taste the same as the same producer's oil pressed in December, and we reflect that in how we curate.

We also believe you should know exactly what you're buying. That's why we list harvest dates, origins, tasting notes, and polyphenol content where available on every product page.

Frequently Asked Questions

What is the healthiest olive oil to buy?

Extra virgin olive oil with a high polyphenol content (above 250mg/kg) and a recent harvest date offers the most health benefits. Look for oils that display their polyphenol content openly — producers confident in their oil's quality will show it.

How do I know if my olive oil is real extra virgin?

Look for a harvest date (not just a best-before), single origin, cold-pressed certification, and acidity level below 0.8%. Genuine EVOO should taste fruity with some bitterness and peppery finish — those are the polyphenols. Bland, odourless oil is a red flag.

Should I refrigerate olive oil?

You don't need to, but it won't harm it. What you do need is to keep it away from light and heat. A cool, dark cupboard away from the hob is ideal. Never store olive oil on a sunny windowsill or next to the cooker.

What is high-polyphenol olive oil?

Olive oil with a polyphenol content above 250mg/kg is generally considered high-polyphenol. The EFSA-approved health claim kicks in at 5mg of hydroxytyrosol per 20g serving. High-polyphenol oils tend to be early-harvest, robust, and peppery in flavour.

Can I cook with extra virgin olive oil?

Yes. EVOO has a smoke point of 190–210°C, which comfortably covers most everyday cooking. Its natural antioxidants make it stable under heat. Save your finest, most complex EVOOs for finishing and dressing where their full flavour can shine.

How long does olive oil last?

Properly stored (dark, cool, sealed), a good EVOO will remain at its best for 18–24 months from harvest. Once opened, aim to use it within 3–6 months for peak flavour. If it smells waxy, musty, or like old crayons — it's rancid. Don't cook with it.