Olive oil production dates back over 2,000 years, with ancient civilizations like the Greeks and Romans pioneering its use. Initially, olives were crushed into a paste using stone mills, and the oil was separated through pressing. Hot water was often used to help extract the remaining oil from the paste. Today, the process has evolved but retains many traditional elements, especially in the production of high-quality oils.

The first step in olive oil production is the harvesting of olives. This is typically done when the olives are in their immature or just-ripening state, as this yields the best quality oil. Olives can be picked by hand or with mechanical shakers. After harvesting, they are transported to a mill where they undergo cleaning to remove leaves, twigs, and dirt.

Once cleaned, the olives are ground into a thick paste. This can be done using traditional stone mills or modern stainless-steel machines. The goal is to break down the olives without damaging the pits, which can impart a bitter flavor to the oil.

After grinding, the olive paste is mixed in a process called malaxation. This step allows the tiny droplets of oil to coalesce into larger droplets, making extraction easier. This process typically lasts 20-40 minutes and is conducted under controlled temperatures to preserve the oil's flavor and nutrients.

The next step involves separating the oil from the water and solids in the paste. This is primarily done using a centrifuge, which spins the mixture to separate the components based on density. The oil is then further purified through a second centrifuge to remove any remaining water and particles.

After extraction, the oil may undergo racking or filtering. Racking involves allowing the oil to sit in tanks, where sediment settles at the bottom. Filtering, on the other hand, actively removes impurities and is becoming the preferred method for high-quality oils.

Before olive oil can be labeled as extra virgin, it must pass several tests to ensure it meets strict quality standards. These tests assess chemical composition, acidity levels, and sensory characteristics. If the oil passes these evaluations, it is bottled and ready for sale.

Olive oil is categorized into several types based on the extraction process and quality:

Extra Virgin Olive Oil (EVOO): This is the highest quality olive oil, made from the first cold pressing of olives without the use of heat or chemicals. It has a free acidity of less than 0.8% and retains the most antioxidants and flavor.
Virgin Olive Oil: Slightly lower in quality than EVOO, this oil has a free acidity of up to 2% and may have minor flavor defects.
Refined Olive Oil: This oil undergoes significant processing, including heat and chemical treatments, resulting in a more neutral flavor.
Olive Pomace Oil: Made from the leftover pomace after the extraction process, this oil is of lower quality and is often used in industrial applications.

The process of making olive oil is a blend of art and science, preserving ancient traditions while embracing modern technology. From harvesting and cleaning the olives to the intricate extraction and bottling processes, each step contributes to the final product's quality and flavor. Whether you prefer the robust taste of extra virgin olive oil or the milder profiles of other types, understanding how olive oil is made can enhance your appreciation for this culinary staple. So, next time you drizzle olive oil on your salad or use it in cooking, you'll know the journey it took to reach your table.

• Extra Virgin Olive Oil (EVOO): Highest quality, made from the first cold pressing without heat or chemicals.
• Virgin Olive Oil: Slightly lower quality with minor flavor defects.
• Refined Olive Oil: Processed with heat and chemicals, resulting in a neutral flavor.
• Olive Pomace Oil: Made from leftover pomace, lower quality, often used industrially.