We know it tastes good, that it's good for us, and that it's the right ingredient for dressing Mediterranean dishes. But what do you need to know to choose the best extra virgin olive oil?
Why does olive oil make your throat tingle? Is green oil better than yellow oil? There are many questions we ask ourselves when choosing the extra virgin olive oil to put on the table. Here are seven useful tips to help you make the right choice.
Read also: Olio extravergine di oliva, proprietà, caratteristiche e benefici per la salute
Using fully ripe olives does not mean obtaining a better oil — quite the contrary. It is from olives at the beginning of ripening, those harvested before the biological cycle is complete, that the extra virgin oil richest in antioxidants is obtained. In organically grown products, the antioxidant content is generally above average. Harvesting on fixed, pre-established dates is not the preferable practice: one must always take into account whether ripening is running early or late, depending on that year's climate.
Like all fats, extra virgin olive oil must be protected from oxidation and contact with polluting substances. Odours, light and heat alter its quality, so it is important to pay close attention to how it is stored. Oil absorbs odours easily — a characteristic that makes it ideal for the production of perfumes, essences, balms and flavoured oils, but that also exposes it to the risk of becoming impregnated with unpleasant smells. A good rule is to keep it away from tins of paint, strongly scented detergents, and rooms affected by mould or saturated with cigarette smoke. Light and heat stimulate oxidation of the oil and the rancidification process. Those who bottle oil themselves should use very clean and dry containers, preferably of dark glass with a screw cap. The metal pourer, so practical for avoiding drips, should only be inserted just before use and then replaced with a screw cap before putting the bottle away. The ideal storage temperature for oil is 15°C: if you do not have a dry, well-ventilated cellar, find the coolest (and darkest) spot in the house. Experts recommend consuming oil within the same year it was produced, because the antioxidant content that protects it from going rancid diminishes over time; however, it remains edible for up to 20 months from pressing. It can therefore be said that the natural antioxidant content of an extra virgin oil, combined with the way in which it is stored, determines how long it will last. Cold does not alter the structure of the oil and does not affect its shelf life.
Young oil is already a product at the peak of its quality. Within one to two months of pressing, extra virgin oil defines its character as its flavours come into balance. It will not improve in the months that follow. Carotenes and chlorophyll are pigments that contribute to the colour of the oil. During storage, chlorophyll degrades and the oil's colour becomes increasingly yellow. Carotenes and chlorophyll both have antioxidant properties. To preserve this property of chlorophyll, it is once again important to keep the oil in the dark.
The colour of olive oil can range from green to yellow, with infinite shades in between. The greener it is, the younger it is: produced from less ripe olives and rich in chlorophyll, a pigment that, as mentioned, degrades over time. When the oil is yellow, it means that carotenes are predominant, and it is equally good. If, on the other hand, the colour tends towards orange-reddish, this means the oil has oxidised and should not be used.
Oil that makes your throat tingle is not the one with the highest acidity — quite the opposite. A slight tingling sensation indicates low acidity and a recent pressing of the olives. What is the purpose of measuring the acidity of an oil in a laboratory? To determine the percentage of oleic acid and to indicate the quality of the product. The higher the acidity, the lower the quality of the oil. It can be raised by poor production practices, namely the use of overripe olives, excessively long intervals between harvesting and processing the olives, and carelessness during processing.
There are three categories: oils with a light fruity character, a medium fruity character, and an intense fruity character. The first tends towards sweetness, is smooth and delicately scented. It pairs well with: fried fish, meat or fish appetisers, white sauces, delicate salads, steamed fish, sautéed bases for seafood dishes, and vegetables in vinaigrette. Medium fruity oil is flavoursome and fragrant, to be paired with: fried freshwater fish, oily fish, creamed legume soups, salsa verde, white meat sautés, marinated fish, fish soup, tomato and mozzarella caprese, field salads and orange salad, marinated tuna, and stuffed vegetables. Intense fruity oil is pungent and makes the throat tingle. It is perfect for robust, full-bodied foods: boiled beef, braised or slow-cooked meat, grilled red meats, legume soups, vegetable soups, ribollita, and bruschette.
Extra virgin olive oil has a very high digestibility rate, higher than that of seed oils and also of butter, lard and dripping. For this reason, extra virgin olive oil is included in the weaning diet for infants.