Producing high-quality extra virgin olive oil (EVOO) involves a series of precise steps, ensuring the preservation of the olive's natural flavors, antioxidants, and health benefits. EVOO is the highest grade of olive oil, made from pure, cold-pressed olives without the use of heat or chemicals. Below is a detailed explanation of the steps involved in producing EVOO:

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1. Harvesting the Olives

The process begins with the harvest of olives, which typically occurs between late fall and early winter. The timing of harvest is crucial because the olives must be at the optimal ripeness for the best quality oil. Harvesting is being done mostly by hand.

 

• Hand Harvesting: Involves picking olives directly from the tree by hand or with the help of tools like small rakes. This method is gentler, causing minimal damage to the olives, but is labor-intensive.

 

Harvesting should be done at the right time—olives that are too ripe or overripe can lead to poorer oil quality, while under-ripe olives may produce oil with a bitter taste.

 

2. Washing the Olives

Once the olives are harvested, they are taken to the factory, where they undergo a washing process. This step removes any dirt, leaves, twigs, or other impurities that might have been collected during the harvest. Clean olives ensure that the oil’s quality is not compromised by any foreign matter.

 

3. Crushing and Malaxation (Grinding)

The next step in EVOO production is the crushing of the olives, which can be done using traditional stone mills or modern steel crushers. The goal is to break down the olive pulp, which consists of the olive flesh and pit, into a fine paste.

• Crushing: Traditional stone mills or modern steel crushers grind the whole olives into a thick paste.
• Malaxation: The paste is then slowly mixed or malaxed for 20-40 minutes. This process is crucial because it helps the oil droplets to aggregate, making the extraction process more efficient. During malaxation, the paste is gently heated to around 27°C (80°F) to preserve the natural flavors, antioxidants, and health benefits of the oil. This is why cold-pressing is important for extra virgin olive oil—temperature must not exceed 27°C to maintain the "extra virgin" classification.

 

4. Extraction of the Oil (Cold Pressing)

Following malaxation, the olive paste is ready for extraction. The oil is extracted through one of two methods:

• Traditional Cold Pressing: The paste is placed in a press (a mechanical device) that applies pressure to squeeze the oil out of the paste. The oil is then separated from the remaining solid matter (pomace) and water.
• Modern Centrifugation (Cold Extraction): This method involves using a centrifugal machine to separate the oil from the paste by spinning it at high speeds. The result is a more efficient extraction process with minimal heat generation, ensuring the oil remains "cold-pressed."

Both methods are designed to minimize heat exposure, preserving the oil’s natural flavors, nutrients, and polyphenols. The extraction must be done at temperatures lower than 27°C (80°F) to be classified as "extra virgin."

 

5. Separation and Filtration

After extraction, the mixture consists of oil, water, and solid residue. The oil is separated from the water and residue using a decanter or centrifuge. The oil is then filtered to remove any remaining particles or impurities, ensuring a clean and clear final product.

Some producers choose not to filter the oil to retain additional flavors and antioxidants, leading to a slightly cloudy appearance. However, most commercial producers will filter the oil to achieve a clear, smooth consistency.

 

6. Storage and Bottling

Once filtered, the oil is stored in stainless steel tanks or glass containers that protect it from light, air, and temperature fluctuations, all of which can degrade the oil. The tanks are often kept in a temperature-controlled environment to prevent oxidation and spoilage. The oil is stored for a short period, typically a few weeks to a couple of months, allowing any remaining particles to settle naturally.

Finally, the oil is bottled for sale. Dark glass bottles or tins are preferred for packaging because they protect the oil from UV light, which can break down the oil’s quality over time.

 

7. Quality Control and Testing

Before being released to the market, EVOO is subjected to rigorous quality control checks. These include both chemical and sensory tests:

• Chemical Testing: To ensure the oil meets the standards for extra virgin olive oil, it is tested for acidity levels (should be below 0.8%), peroxide value, and other chemical markers that indicate freshness and purity.
• Sensory Testing: Trained tasters, conduct blind tasting sessions to assess the flavor, aroma, and overall quality of the oil. Extra virgin olive oil should have a balanced, fruity flavor with no defects (such as rancidity or fustiness) and a pleasant aroma.

 

8. Labeling and Distribution

After the extra virgin olive oil passes quality checks, it is ready for labeling. The labeling process is essential as it communicates important information to consumers, including the olive variety, harvest year, region of production, and the certification of extra virgin status. Olive oils that meet organic or PDO (Protected Designation of Origin) standards may also have additional labels.