The quality of the oil is obtained from the culture technique: balanced fertilization and well-dispensed; annual pruning or every two years at the most, treatments to help the defence of the plant given only when necessary. To guarantee the conservation of the components responsible for the aroma, colour and oil flavour, the olives must be picked at the right degree of maturity (D.O.P disciplinary of terra di Bari imposed within January 31st ). A good quality oil is obtained from olives not picked from the ground but directly from the plant, either manually or with vibrators, combs vibrators, small rakes, etc.

The quality of the oil is greatly affected by the olives’ working technique adopted in the oil mill. Once the oil is obtained, for a good conservation, the most convenient containers are for the greater quantities, the ones made out of stainless steel and the postures with walls coated with water-base fibreglass lining; for small quantities (family consumption), the use of dark glass containers will be ideal.

It is good practice, for the non-filtered oils to decant at the beginning of springtime in well-cleaned containers to make sure that the oil will be free from any unpleasant odour that would negatively affect its quality and value. It is important to remember that the oil must be stored in cool, dark places and that light and higher temperatures can alter the oil product.

Organolectic Properties

The final oil features depend on the olive qualities and on the working technique applied, during which the oil contained in the pulp oleic cells comes into contact with other chemical components of the olive, originating organolectic and quality properties. These altogether are responsible for the presence of properties as colour, odour, taste and so on and their qualities correlation brings about the qualities that make an oil peculiar to a specific territory. In fact, it is possible to obtain very good oil from a chemical standpoint (0,3° – 0,5° acidity; peroxides numbers of less than 10, etc.) but with organolectic deficiencies (soil odour, reddish colour, etc.), which affect the consumption: at this point it becomes necessary to evaluate the oil with a sensorial analysis which is obtained through a “panel test”.

It is a mandatory evaluation, introduced by the Reg. CE 2568 /91 regional by law and part of the disciplinary of the “Terra di Bari” D.O.C. The panel test consists of a tasting session by a group of experts, who, with the help of an evaluation form, give points to the product of examination. A good extra virgin olive oil must obtain a total average not inferior to 6.5. The colour is the first aspect to be observed by the consumer. A good oil must have a greenish-yellowish colour more or less depending on the olive maturity: colour variations are indications that the product could be older or altered. A fresh oil easily releases its odour that faster disappears in the following months the less priced the oil is.

The flavour is typical of every oil, it is also due to a reaction of the substances contained in the olive, with the sensorial/sensitive mouth cells. The presence of antioxidant substances “Polifenols” gives the oil a sensation of bitterness and spicy flavour (typical of the Corato variety) and in the right intensity contribute to the sensation of the creation of a more pleasant yield. The antioxidant substances diminish in time and this explains why older oil is sweeter.