1. Olive oil is first extracted by cold pressing, then potentially "treated" with various chemical and mechanical processes. The difference between EVOO and other types of olive oil (light, extra light, etc.) is the level at which the oil has been processed.
2. EVOO means Extra Virgin Olive Oil. Pure EVOO has not been chemically processed. The taste of pure EVOO tastes "green" - you can taste that it is from an actual plant. Extensively processed oils will not have this taste. Organic EVOO is the most pure - the plant and its oil were not genetically modified nor exposed to any pesticides and harmful chemicals.
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