Single Variety and Mono Cultivar
The variety or cultivar selected for planting will certainly have an effect on the overall flavor and characteristics of the oil, but the characteristics and relative merits of individual cultivars are hotly contested. Although most table fruit is unsuitable for oil production because of yield, size, and oil content there are always exceptions. It is also notable that many of the attributes ascribed to single varieties disappear when planted in other regions with different soil conditions and microclimates.
This complicated subject is woven happily and inextricably into the unique fabric of the area where each variety is grown negating the attitude that one cultivar is superior to the rest. Variety in olive oil as in all things is indeed the spice of life.
The following list of cultivars accounts for the major percentage of all olive oil produced in the world today, but represents only a fraction of the known cultivars. Each has its unique characteristics, but some differences are remarkably subtle. Some are more durable, while others hold up better to heat. Some are rich, soft and buttery while others are big, angular and complex. The choices are delightfully limitless. Most are not sold as single varieties, except in the regions where they are produced or at specialty import stores with ridiculously high price tags that cause embarrassment to the purchaser. The vast majority ends up being part of some generic olive oil blend marketed under any one of dozens of different brands or labels around the world.
There is no substitute for personal experience. Try as many olive oils as you can. When you purchase in bulk from single cultivar stocks you will be surprised to find and be rewarded by the rich variety and quality available at nearly the same price as branded generic olive oil.