Does the harvest time play a role for the quality of olive oil?
A clear no to this question. But there is a more important question:
Does the harvest time influence the resulting olive oil?
Yes and not. Yes because it plays a role in terms of taste and color. No because it does not play a role in terms of quality.
The time of harvest refers to the time when the olives are picked from the tree. But it does not affect the processing and labeling of the oil. Any extra virgin olive oil can be obtained form an early or a late harvest. Though the harvest has an influence on the taste of the oil, it does not change the quality.
The harvest time will influence the bitterness of the oil. But a bitter and spicy taste is a positive indicator for a good extra virgin olive oil. If you ever tried to eat an olive just picking it from the tree you will clearly remember spitting it out as fast as you could. Olives in these state are very, very bitter. Therefore a good olive oil will retain a bitter taste, as it is the juice of fresh fruits. But it will not be as bitter as a single olive you pick from the tree. The same applies to the spicy taste, it is proportional to the intensiveness of the olive fruit.
There are varieties with a more intense flavor likes the "Picual", and other sweeter olives like "Empeltre". Both oils will have different bitterness, but they will both have some bitter taste anyway.
The color of an oil reveals something about the point of ripeness of the olives. Dark green will be typical for olive still very rich in chlorophyll, with a very fruity and bitter taste, like the olive that did not reach the full ripeness.
There is an ongoing debate over the best harvest time between Spanish oil producers. It is an old discussion. Nowadays there is a tendency to very early recollection, but many oil producers still prefer to harvest as late as possible to obtain oil with higher fat levels. This discussion may be as old as the olive oil production itself. Older practices from 19th century recommended to follow always the nature, the climate of each region and the soil conditions, making it impossible to state a defined day, week or even month for the best time to harvest.
In France, Italy and northern Spain recollection often started in December, January or even in March or April. In some regions in Italy is was not collected until the point when the olives fall to the ground, while in others they picked the fruits in January or February, waiting as long as possible to get a black color before the first frosty days.
In Jaén there has been recollection in mid October until November for centuries, because at this time the olives reached their biggest size and oil levels. But now many producers have started to collect the olives earlier to get the still green fruits. The reason is mainly the taste. A greener oil has a very delicate taste and a clearer consistence. In the Andalusian provinces of Cádiz and Huelva, olives are collected in October, as this is the month where they are at their best point.
Another reason is that picking the olives at a very late point can lead to the typical alternation of a good year followed by a weak year. Getting the fruit from the tree at an earlier point will stabilize the productivity of the towards a steady number of fruits for evevery year.
The harvest time for olive goes from the end of autumn to the beginning of winter for Andalusian producers that prefer an early recollection. Andalusia and most parts of Spain still enjoy mild climate conditions during these months, therefore the olives usually do not freeze at this time of the year.
The harvest time in other regions of for ripe fruits will start at the end of November and finish in February or March, sometimes even later. In colder climates the harvest time will be earlier to avoid any frost that could lower the quality of the oil.
Different grades of ripeness lead to different color and taste
As we see, harvest time has a direct influence in the composition and taste of the resulting olive oils.
Depending on each olive type, the fruits are recollected when they reach their highest level of acid fat in the pulp. As the maturation process evolves, the olives change their properties and flavors loose intensiveness and the taste is smoother and sweeter. The color also changes towards ripeness. At the beginning of the harvest time the fruits are green and the resulting oils will be much greener and bitter than at a later point for the same olive type. As the olive ripens the color of the oil tends more to yellowish or even golden, as the fruits start lowering the chlorophyll-carotene ratio.
If the harvest time is too late, the olives will already be falling off the trees and will suffer alterations that will also lower the quality of the oil as the acidity levels rise once the olive leaves the tree and falls onto the soil.Therefore the olive picked from the tree and the olives that already fell of are separated carefully during the recollection to avoid mixing the different quality. This could result in not passing an extra virgin test and losing money.
Resuming: There is no difference regarding the quality of an olive oil from an early or a late harvest. It is more an issue of taste and aroma. Nevertheless, the best oils often come from fruits at the zenith of ripeness, just before the olive starts to change color from green to dark.
Olive oils from early harvest
An early harvest, meaning that the olives were harvested just before their ripe point while the olive were still green, will make a slightly bitter, dark green oil with a spicy taste. It is a very fine oil that some chefs value very much for specific recipes. As the earlier harvest leads to smaller olives, an extra virgin oil from early harvest often will be more expensive, as there is more fruit needed to obtain the oil.
Green olive oils come from unripe olives and impart a slightly bitter, pungent flavor. Emerald-tinged oils have fruity, grassy, and peppery flavors that dominate the foods in which you use them. These oils are great with neutral-flavored foods that allow their bold flavors to shine. You can pair green olive oils with strongly flavored foods as long as they complement the oils' pungent tastes.
Olive oils from late harvest
Oils from late harvest on the contrary result in sweeter oils with a fruity taste. The fully mature olives are sweeter and richer, so the resulting oil is smooth and very tasty. Yellow-golden oil will be an indicator of ripe olives from a late harvest. In sweet, golden and tasty Andalusian extra virgin oil matches perfectly for the soft bagels you eat for breakfast with just olive oil, some salt and maybe some tomato. A good olive oil on toast tastes like heaven.
Olive oils that glimmer with a golden color are made from ripe olives. Olives turn from green to bluish-purple to black as they ripen. Oils made from ripe olives have a milder, smoother, somewhat buttery taste without bitterness. These oils are perfect for foods with subtle flavors because the gentle taste of a ripe olive oil won't overshadow mildly flavored foods.
