When the fruit is harvested is arguably the most critical and yet least understood variable when it comes to producing fine olive oil. Both the yield (overall cost) and the organoleptic characteristics of the oil are dramatically affected by this decision. Since it is not possible to harvest and crush every olive at the precise optimum moment of ripeness, certain compromises must be made. More northerly producing regions are forced to harvest earlier because of the danger and likelihood of frosts and freezing temperatures. The economic considerations of keeping a mill producing for the maximum amount of time also affects the overall cost and ultimate quality of the finished product. In general, the longer the mill can stay in production the lower the cost to produce. This means producing over a period of time and therefore spectrum of ripeness.

Theoretically, there exists an exact moment when ripeness and acidity levels are at their respective optimums in every olive. Crushing the fruit before this imaginary "moment" or peak of ripeness will translate to a lower yield and greener tasting oil. "Grassy" or greener tasting oil is the result of higher levels of chlorophyll still held in the fruit. Crushing the fruit before it is ripe does provide one major benefit: the acidity levels are much lower in unripe fruit. Since the primary chemical test for grading olive oil focuses on the acidity level, this early harvest oil is sometimes cynically referred to as the "VIRGIN MAKER." The lower yield, and bitter tasting aspects resulting from crushing olives before they are ripe can be offset by using this oil as a blending agent that serves to lower the acidity levels of oils that might not otherwise meet the chemical standard. Early harvest olive oil can also provide a semblance or note of freshness to oils that are otherwise tired.

Conversely, crushing olives that are overripe will produce olive oil that is smoother and softer in its inherent intensity and sought after fruity characteristics. The practice of letting the fruit become overripe on the tree has the significant economic benefit to the crusher of increasing the overall ratio and yield of oil to olive by weight. This, of course, lowers the cost of the oil in a big way. The acidity level, (free fatty acids or ffa’s) rises as the fruit begins to decompose increasing until it is unfit for human consumption unless it is first refined.

This is one of the main reasons why there is so much refined olive oil produced. Farmers that let their olives become overripe on the tree are rewarded economically by a very high yield. The difference in yield from early harvest oil (12% to 16% oil to olives) and late harvest yield (20% to 28%) is significant ( This difference equates to an increase in yield between 33% and 133%) Today the “world market price” that separates refined olive oil from extra virgin olive oil is less than 12%. There are times when the prices between these two drastically different products are virtually nonexistent.

The competing interests of yield, acidity level, and flavor profile make when the olive is crushed the single most important consideration when it comes to producing high quality extra virgin olive oil. If the fruit is crushed before it is ripe it will be excessively expensive and the oil will have a bitter less fruity chlorophyll taste. If the fruit is allowed to become too ripe then it will be unfit for consumption unless it is first refined. When either consideration of higher yield or lower acidity level becomes too dominant the cost and quality of the oil suffer. It seems fitting that a balanced approach is the most rewarding one.