---
title: "Everything I Know About Olive Oil (It Took 10 Years to Learn)"
created: 2025-08-14 11:00
author: Amelia Fontaine
keywords: olive oil, extra virgin, cooking, polyphenols, sourcing guide
description: Pressing methods, polyphenols, smoke points, fraudulent EVOO, which to cook with versus finish with, and a practical sourcing guide.
---

# Everything I Know About Olive Oil (It Took 10 Years to Learn)

I have been thinking about olive oil for ten years and I am still not sure I understand it fully. It is, in the world of cooking ingredients, unusually complex — variable by region, variety, vintage, harvest date, pressing method, and storage — and the fraud rate in the industry is high enough that even careful shoppers are routinely misled.

What follows is what I have learned, mostly through buying, tasting, cooking, and occasionally ruining things.

## What "Extra Virgin" Actually Means

Extra virgin olive oil (EVOO) is produced by mechanically pressing fresh olives — no heat, no chemicals — and meeting specific quality standards: free acidity below 0.8%, and organoleptic standards requiring the oil to have positive attributes (fruitiness, bitterness, pungency) and no defects (rancidity, mustiness, winey notes).

The category below this is "virgin" (acidity up to 2%, some defects permitted), and below that is "olive oil" — a blend of refined oil (chemically treated to remove defects) and virgin oil. These are quite different products.

The problem is that "extra virgin" on a label guarantees very little in practice. The fraud issue is substantial: studies repeatedly find that 50–80% of olive oil sold as Italian EVOO in international markets either fails quality standards or has been diluted with other oils. The EU has certification systems, but enforcement is inconsistent.

## How to Buy Better

The indicators of genuine quality:
- **Harvest date**: Look for it on the label. EVOO is perishable — it should ideally be used within 18 months of harvest and definitely within 2 years. "Best before" is a poor proxy; harvest date is what matters.
- **Single origin, single estate**: Oil from a single producer in a specific region is more verifiable than blends.
- **PDO/PGI designation**: Protected Designations of Origin (Tuscan EVOO, Kalamata PDO) have more rigorous controls.
- **Tin rather than dark glass**: Light degrades oil. Opaque tins are the ideal container. Clear glass is the worst.
- **Peppery burn**: Good EVOO — especially Tuscan and Sicilian varieties — should cause a noticeable burn at the back of the throat when tasted neat. This is the polyphenols, and it is a quality marker, not a flaw.

## Polyphenols

Polyphenols are the antioxidant compounds in olive oil, associated with most of its health benefits and responsible for the distinctive bitterness and pungency of high-quality oils. Early harvest oils (October-November, before full ripeness) contain more polyphenols but are more aggressive in flavour. Late harvest oils are milder and rounder.

High-polyphenol olive oils — which are increasingly available from specialist producers — have measurements above 250mg/kg on the label. These are robust, almost savoury, and can taste almost bitter neat. They are extraordinary for dressing strong-flavoured foods.

## Smoke Point and Cooking

The great misunderstanding: "olive oil has a low smoke point and shouldn't be used for high-heat cooking." This is largely wrong. **Extra virgin olive oil's actual smoke point is 190–210°C**, depending on quality and age. This is more than sufficient for sautéing, shallow frying, and roasting. The smoke point of cheap refined oils is often higher, but polyphenols in EVOO make it more oxidatively stable at high temperatures.

The practical advice: do not deep-fry in EVOO (the economics are prohibitive and the smoke point, while adequate, gives less margin). For everything else — sautéing, roasting, making dressings — extra virgin is fine and often produces better flavour than neutral oils.

## Finishing vs. Cooking

There is a meaningful distinction between oils used to cook with and oils used to finish dishes. Cooking oil gets hot; much of its aroma evaporates and its flavour integrates into the dish. Finishing oil goes on cold or room-temperature food and its full character is experienced directly.

For cooking: a mid-range EVOO (£8–12 for 500ml) is excellent and economical. The heat will integrate rather than present its flavour.

For finishing: this is where a genuinely exceptional oil earns its price. A Sicilian *Nocellara del Belice* (full, fruity, grassy) or a Tuscan *Moraiolo* (pungent, bitter, peppery) drizzled over bruschetta, soup, fish, or legumes transforms the dish in a way that a cooking oil cannot.

## Storage

Away from heat, away from light, used within 6 months of opening. Not next to the stove; not on a windowsill; not in a clear bottle on a kitchen counter. In a cool cupboard, in a tin or dark bottle, used regularly. Rancid oil — which smells of crayons or old butter — is the most common quality problem and entirely preventable.

## The Practical Upshot

Buy from a specialist importer or directly from a producer if you can. Look for a harvest date. Spend more on the finishing oil you taste directly; spend less on the cooking oil the heat will transform. Keep it in the dark and use it promptly. Taste it out of the bottle sometimes — you will learn more about it that way than any other. It should make you want to eat something.
