The remainder is harvested for table olives which, though there are over 2,000 known olive cultivars, are known to … different curing processes combined with different varieties are how we get different types. Oils made from ripe olives tend to be a golden- or light-yellow color. Basically, olives are pressed through a machine and oils are collected while the rest of the olive is discarded. The methods are different depending on which grower you ask, but olive oil itself is made before the olives turn black. About 90 percent of the world’s olive crop goes to make olive oil. The black olives used in the food service industry are ‘made’ black by adding oxygen during the curing process, which helps to mellow the bitterness. The best time to make olive oil is right after they ripen, when they are green. You may have seen this term on some of your favorite healthy smoothies more recently. How Extra Virgin Olive Oil is Traditionally Made. if you prefer a sharper-flavored oil, you would use more green olives than either fully ripe or partially ripe in the mix. Olive oil is pressed from a blend of unripe, partially ripe, and fully ripe olives. Olive oils made from unripe, green olives have a light- to deep-green color. Typically, extra virgin olive oil is made at large mills by a method called cold-pressing. Olive oil is usually made from completely different varieties. For a sweeter-flavored oil, the mix is 1/4 green, 1/2 partially ripe, and 1/4 black.