How is extra virgin olive oil made?
Extra virgin olive oil (EVOO) is a high-quality, unrefined olive oil made from olives through a cold-pressing process that does not involve heat or chemicals.
The production of EVOO involves grinding olives and pressing the resulting paste to extract the oil. This is achieved by cold-pressing the olives at room temperature, which helps to preserve their flavour and nutritional properties. As a result, EVOO is rich in natural vitamins, minerals, and antioxidants.
Here are the detailed steps involved in the production of olive oil:
1. Olive Harvest
Olives are harvested, either manually or mechanically, and then transported to the oil mill.
2. Cleaning
Upon arrival at the oil mill, the olives are cleaned to remove leaves, debris, and any foreign objects. This is often done using machines like deleafers and washers.
3. Grinding
After cleaning, the olives are crushed into a paste, usually within 24 hours of harvest. This can be achieved using stone mills or other mechanical methods.
4. Mixing
The olive paste is then mixed, often with a machine designed to mix and knead the paste while controlling the temperature. This step helps aggregate the oil droplets, preparing them for extraction.
5. Oil Extraction
Next, the olive paste is separated into its components: oil, water, and solid residue. This separation can be accomplished through methods such as centrifugation, decantation, or pressure.
6. Filtration
The extracted oil may then be filtered to remove any remaining solid particles.
7. Bottling
Finally, the olive oil is bottled and stored in a cool, dark place to maintain its quality.
What classifies an olive oil extra virgin?
To be classified as extra virgin olive oil, the oil must meet certain strict criteria regarding taste, aroma, and acidity. EVOO can have a maximum of 1% free fatty acids, expressed as oleic acid, per 100 grams. Its flavour is characterised by a light peppery taste, and its colour is typically golden-green due to the presence of chlorophyll and pheophytin.
Important note!
The high quality of extra virgin olive oil is what makes it the most expensive type of olive oil. It differs from other varieties because it is unrefined and meets strict quality standards. However, it’s important to note that the colour of different brands of olive oil can vary, and this should not be used as a definitive indicator to differentiate between the various grades of olive oil.
Written by:
Katerina Kouloumenta,
Nutritionist/Dietitian