For thousands of years olive trees have grown on Mediterranean shores becoming part of the rich heritage of ancient societies like the Phoenicians, Greeks, and Romans. Olive oil found a wide use, ranging from medicine to lighting whole cities. Diets revolved around this delightful oil, adding a delicate aroma and flavor to dishes. In fact, the olive tree became so entwined in their culture, olive branches symbolized peace and friendship and even crowned the heads of winners in Olympic games.

Now in the 21st century researchers have discovered people living on a Mediterranean diet enjoy longer lives. Likely due to its extensive anti-oxidant properties, olive oil lessens heart disease, promotes healthy digestion, makes for healthy skin and is viewed as a preventative for cancer and diabetes.

Despite its many redeeming qualities, all olive oil is not the same. Much like fine wine experts, olive oil experts grade olive oil on its aroma and flavor. Usually eight to ten professional tasters will gather in a room to sample the oil. They sample it from opaque glasses, hiding the color so it doesn’t influence the tasting. Excellent quality oil varies in color from yellow to green. The type of olive and its ripeness will determine the color. Some of the finest oils come from the least ripe olives, making it spicier while other olive oils taste fruity. The tasters grade it on a scale from one to nine, nine being the highest, based on the pleasantness of the taste.

However the taste test doesn’t include examining acidity. A second test, done by laboratory testers, analyzes and grades acidic properties.