1. Natural Environment
The Olivar de Sierra mountain olive grove is in a practically unique location, where the olive groves are integrated into their natural environment. This rugged terrain hinders agricultural mechanisation and this is why they still use traditional cultivation techniques, trying to avoid erosion through non-tilling techniques and maintaining spontaneous plant cover in the areas not occupied by olive trees.
a) Presence of the native Nevadillo Negro variety
The natural blend provided by the presence of Picual and Nevadillo Negro in variable proportions is unique and exclusive to Montoro-Adamuz oils. Distinctive features resulting from this blend are its high level of polyphenols, which give the oil its characteristic bitter and peppery taste, and its ability to keep very well, a feature which has ensured that this oil has been appreciated since time immemorial.
The Nevadillo variety is native to the geographical area demarcated by the “Montoro-Adamuz” Designation. The agricultural region of the Sierra de Córdoba is where most specimens are located, coinciding with the same area as the “Montoro-Adamuz” Designation. So, a surface area of 10,000 hectares is within this demarcated area, representing around 20% of the protected area of olive groves. It is therefore a variety that is well adapted to the conditions of water stress, acidic soils and shallow soil that are present in the area, and they are the oldest cultivated varieties, being catalogued as specimens for almost 500 years by the Dept. of Agronomy at the School of Agricultural and Forestry Engineers at the University of Córdoba.
b) Soil features.
The soils of mountain olive groves in the “Montoro-Adamuz” Designation, which are acidic, poor quality and shallow, are unlike the normal Andalusian olive groves which are generally found on alkaline soils, mainly with a chalky nature.
The olive tree in general is better suited to those alkaline, or in other words neutral and limestone, soils which are found across almost all of the Spanish olive producing surface area, making this demarcated geographical area an exception within Southern Spain.
c) Climatic features
Temperatures are characterised by a very sharp contrast between the warm summer and cold winter seasons and it has low average rainfall, which is concentrated into the winter and spring. The region has hillsides, a steep topography, an average altitude of 425 m, is south-facing and has a high level of sunshine.
The difficult soil conditions (shallow soil, low fertility and acidic soils) are even more noticeable when cultivating olive groves due the high levels of evapotranspiration and degree of sunshine that the region has in summer and autumn, the time when the fruit form and ripen. The region has one of the highest levels of evapotranspiration in Andalusia.
These agricultural conditions, together with the steep slopes that exist throughout the district, cause high erosion and therefore a shortage of soil which accentuates the water shortage for the crop in summer and autumn.
The specific features of the geographical area have led to the development of the native Nevadillo Negro variety, perfectly adapted to this extreme environment, strongly resistant to drought and shallow soils (hardy variety). This variety is found in the form of ancient olive groves dotted around the area’s plantations and it represents up to 20% of the olive producing surface area.
2. Human factor
The demarcated geographical area has a steep topography with large sloping areas, average slopes of 23%, which are similar to the average values of the olive producing areas in the steepest parts of Andalusia. This average slope in the olive producing areas covered by the Designation determines the practice of early harvesting which is performed in the area in order to avoid the dropping of the olives as a result of the winter rains.
3. Specific product features
The specific features that define the “Montoro-Adamuz” oils are due to their high content of polyphenols, these being responsible for the characteristic bitterness of the oil and for giving it great chemical stability against oxidation, a feature which has ensured that this oil has been appreciated since time immemorial.
This content of polyphenols is much higher than found in other commercial oils (Extra Virgin Oil) and also in those from other areas of Southern Spain.
In addition, the sensory attributes, such as the “fruitiness of the olive” and “green leaf”, can be seen from the high intensity, median of fruitiness of greater than 4.
4. Causal relationship between the geographical area and the quality of the product
The high content of phenolic compounds in the oils from the “Montoro-Adamuz” designation, over 700 ppm, is directly related to the presence of the Nevadillo Negro variety, resulting from the extreme agro-climatic growing conditions that cause physiological stress to the olive tree and require early harvesting.
The blend provided by the presence of Picual and Nevadillo Negro in variable proportions is unique and exclusive to Montoro-Adamuz oils. Distinctive features resulting from this blend are its high level of polyphenols, which give the oil a characteristic bitter and peppery taste and its ability to keep very well, a feature which has ensured that this oil has been appreciated since time immemorial.
The extreme Mediterranean climatic conditions, with a high average temperature and large amount of sunshine, moderate rainfall that is markedly seasonal, together with a high annual ETP, between 800 and 900 mm, result in a significant water shortage effect when cultivating the olives. This is accentuated by the soil conditions in the region: acidic soils, steep slopes, soils that are shallow, contain stones and with low fertility, established on acidic materials. All of this results in a physiological stress to the olive tree that causes an increase in the polyphenol content.
The steep topology, with the olive groves situated on hillsides with steep slopes, has led to the early harvesting of the olives being a practice firmly rooted in history. This practice entails only harvesting olives from the trees, preventing the fruit from dropping to the ground. This is because it is impossible to collect them from the ground due to the high costs associated with the lack of mechanisation for mountain olive groves of this type. In addition, this early harvesting also results in a higher quality product.
Moreover, the early harvesting of the fruit, which is a deeply rooted cultural practice in the region, taking place from 15 October to 15 January, has an impact on the maximum content of polyphenols and provides some extraordinary organoleptic qualities to the oils, which are defined by a median of fruitiness of > 4, in which the sensory attributes of the “fruitiness of the olive” and “green leaf” can be found with the utmost intensity.
Our virgin olive oil is obtained from the olive varieties that exist in our districts: Picual, Nevadillo Negro, Lechín de Sevilla, Picudo and Carrasqueño de la Sierra.
The Picual and the native Nevadillo Negro are considered the main varieties. This combination represents 98% of the DO olive oil production.
These olives give a unique and exclusive flavour to our oils. The Nevadillo Negro is one of the varieties of olive richest in polyphenols (see study). The high content of polyphenols gives the oil its characteristic bitter and peppery flavour as well as excellent stability against oxidation.