Among the agricultural work in autumn, the olive harvest stands out in many parts of Spain, which involves the producers and immediately after the oil mills that have the task of extracting the precious oil from the fruit. It is usually a typical activity at the end of October, November or December, but the period varies depending on the type of olive and the seasonal weather.
The most appropriate degree of ripeness is different depending on the use: if table olives are cultivated, they are picked ripe, while to make oil it is best to take them before they are fully ripe, otherwise a more acidic oil will be obtained, which loses much of its nutritional properties and aroma. Therefore, for the quality of the oil, it is very important to learn how to choose the right time for harvesting.
The method of harvesting in the olive grove can also lead to a better or worse result, and care must also be taken not to damage the tree with dedicated tools to facilitate the work. Indeed, motorized pickers or combers must be studied and used conscientiously so as not to mistreat the olive trees.
Harvest time in the olive grove
The period indicated for harvesting the olives varies between October and January, several factors influence it:
- The climate of the region where it is grown and harvested.
- Exposure to the sun of the olive grove.
- The variety of olives (there are late and early).
- The purpose of the harvest (table or oil).
After the harvest, once the winter frosts have passed, depending on the weather between January and April, the pruning period for the olive trees begins.
Harvest olives at the right time
When to harvest is a big dilemma for olive growers: taking them in advance means getting better oil, but sacrificing quantitative yield because the fruit contains less oil. Leaving them longer on the plant also puts them at risk of falling off or being destroyed by insects like the olive fly. It is worth going into more detail, assessing the risks and opportunities at each stage of maturation.
Maturity levels and risks
Olives go through several stages from immaturity to maturity:
- unripe olives meat very tough and still forming.
- herbaceous olives : the herbaceous stage is the initial moment of ripening, the fruits are still green and hard, rich in chlorophyll. If harvested during this time, the olives give life to a very fruity oil with spicy notes and excellent antioxidant qualities. The period of this stage is generally from the end of September for the early varieties, until the end of November for the late olive trees. Harvesting olives at this stage has a lower oil yield, but is less affected by the risk of oil fly attacks.
- veraison olives . At this stage the olive changes color, going from green to purple. Being the moment when there is a higher concentration of polyphenols, the oil is of better quality, both nutritionally and in terms of its aroma. In most cases, it is considered the best time to harvest olives for oil.
- full ripening . Olives have fully colored skin. The productivity of the olives in terms of the amount of oil is optimal, although they lose some quality as they ripen. It is the ideal setting for harvesting table olives.
- Overripe. The fruit begins to fall to the ground, the oil obtained is of lower quality, with a less intense flavor, although from the point of view of quantity the yield is guaranteed. The fermentation of a ripe fruit generates a higher acidity. Mold and rot can occur, especially on fruit picked from the ground.
As the olives mature, their resistance to detachment decreases. : Ripe olives will come off very easily, herbaceous ones will be very resistant. If on the one hand easy detachment is conducive to harvesting, especially if it is carried out with shakers or other mechanical means, on the other hand, when the olives ripen, heavy rain is enough to cause the fruit to fall prematurely, ruining a good part of the harvest. In addition to the fall to increase the risk factor, there is the troublesome oil fly parasite of the olive tree which can damage the fruits during their maturation, the collection of the most immature fruits does not pose a problem.
When to Harvest Table Olives
Table or table olives must be harvested very ripe, so they must have reached their maximum size, which depends on the variety, and their final color, which also varies according to the type of olive. The pulp of the fruit must be soft and juicy, not hard, so that it is pleasant to eat. This type of olive should preferably be harvested by hand, or in any case with tools that do not spoil the fruit, which, being completely ripe, is more delicate.
When picking olives for oil
The moment of the olive harvest is decisive for the organoleptic and nutritional characteristics of the oil that will be obtained, as well as for its quantitative yield. There are different points of view on the best moment, but in general, the veraison stage is chosen which, due to its content of phenolic substances, makes the oil more precious and aromatic.
In this way, it is used for consumption and cosmetics, since the oil is present in thousands of beauty products, from children’s cream to shaving balms for men.
After the harvest it is important that the pressing is done in two days maximum, the ideal would be to bring the crusher the same day.
There are several ways to pick the olives: you can choose to do it by hand, which is still the best way to ensure high quality, or to get help from different types of mechanical tools. Let’s see a summary of the most common methods.
- Manual collection or burning . Taking the olives one by one is the best way to choose them carefully so that they are all in the right place and undamaged. This is obviously a time consuming method and can be difficult in a large olive grove.
- Backstab or shoot. This popular technique relies on nets placed under the plants, then the sticks are shaken, knocking out the fruits that are ripe enough to fall. There are mechanical beaters to make this operation less difficult. The defects are the possibility that the olives are damaged during the fall, the wrong selection that is made and the possible damage to the branches during the work.
- Manual collection with nets . A middle way between drilling and punching is collecting with the use of netting, tongs can also be used to aid in picking up, expanding your work area.
- raking . In this case, combs are used to remove the olives from the branch and deposit them in the nets.
- Tremor. Another alternative to shaking is the shaking of branches, a job that is carried out with the help of special shakers, usually motorized and of good power.
- Collection. If you decide to pick the fruit from the ground, expecting it to drop spontaneously, you will very often pick moldy, weakened, or overripe olives. For this reason it is a method to be avoided.
Useful tools for harvesting olives
Depending on the method chosen, there are different types of equipment that can help with harvesting operations. A common aid to most types is the olive fillet, a good option can be found which can be purchased online here.
There are several types of mixers, mechanical ones that can be explosion or electric, which, being lighter, are more widespread. Shakers, on the other hand, are usually internal combustion for the higher power they require. A range of harvesting equipment can be found online here, ranging from professional models to inexpensive solutions for those with few plants.
Once harvested, plastic boxes are used to contain the olives, with perforated walls, without exaggerating the overlap that would squeeze them.
These fruits keep for a short time after harvesting, so if you want to keep them on the table you have to treat them quickly for their conservation (brine, vacuum,…), while to make the oil you have to bring them to the mill, ideally within 24 hours and in any case before 48 hours to maintain the quality of the oil and the delicate flavor and low acidity.