Verifying whether olive oil is 100% pure involves checking the bottle for specific indicators, such as a certified harvest date, country of origin, dark glass packaging that protects against light degradation, and official quality seals like PDO (Protected Designation of Origin) or extra virgin certifications. Additionally, consumer taste tests looking for a fresh, fruity aroma and a slight peppery throat burn help confirm authenticity over refined or adulterated vegetable oil blends.