We all know the health benefits of olive oil, its importance in the Mediterranean diet and of course its incomparable taste. But do you know how to choose a good olive oil? Here we shall give you some tips so that you can recognise which type is best suited to your needs. Why is olive oil believed to be healthy? Olive oil is a source of monounsaturated fatty acids which help reduce levels of LDL cholesterol, better known as bad cholesterol, in the blood. It contains antioxidants, polyphenols and vitamin E, which protect the cells from cancer and arteriosclerosis. It also benefits our digestive system: olive oil aids digestion and also has an antibacterial effect, thanks to the polyphenols it contains. Why don't olive oils all taste the same? Olive oil is 'the juice of olives', and therefore its taste depends on the characteristics of the olive variety, where the olives are cultivated and the harvest of any particular year. For this reason, there is a great variety of flavours, from smooth, 'sweet' ones to those with bitter or peppery notes of various intensities. What does olive oil acidity mean? Acidity is a chemical value and cannot be noted in the taste. The acidity of an olive oil gives us information about the quantity of free fatty acids present in the oil. The lower the acidity, the better the olive oil. For example, for extra virgin olive oil the maximum permitted acidity is 0.8%, while for virgin olive oil the maximum value is 2%. What does bitterness in olive oil mean? Bitterness is a characteristic of olives, as is spiciness. These two attributes, together with fruitiness, are present and well-balanced in the best extra virgin olive oils. Therefore, we should look for and certainly know how to recognise and value these attributes. Do you want to know why? Bitterness is a fundamental and very characteristic flavour in virgin oils. If the olives have been harvested while they are green, or when they are beginning to ripen (when they still have not turned a darker colour), they retain their unique bitter taste. Phenols (a class of chemical compounds) including oleuropein are responsible for the bitterness and are antioxidants. When these compounds are not present, or are present only in very limited amounts, this renders oils sweeter in taste. The sweetness of an oil is measured not by its sugariness but by its lack of bitterness, astringency or pepperiness. In contrast to the sweetness or bitterness of an oil, its pepperiness is not a flavour. It is a spicy sensation which a lot of oils have, especially those produced at the beginning of the season. Normally these are virgin oils that have been made with green olives, as is the case when bitterness is present too. As with bitterness, pepperiness is directly proportional to the quantity of phenols that the olives contain, or in other words the quantity of antioxidants. The fruitiness of an olive oil can be noted in its smell, which should evoke fresh, healthy fruit. This is why it is something that we should recognise and value when we taste an olive oil, since it is a sign of quality. What colour is a good olive oil? The colour of an olive oil is not an indicator of its quality or taste, but of the month in which the olives were harvested, the type of olive and its degree of maturation. In fact, olive oil tasting is performed using blue glasses so that the taster does not pay attention to the colour of the oil. Does olive oil lose it properties when it is heated? Olive oil does not lose any of its properties when it is heated, nor any of its nutritional content, although its flavour changes slightly. When it is heated, the alcohol and esters evaporate, and it is these which give the oil its flavour and aroma. In comparison with other vegetable or animal fats, olive oil is that which is best able to stand high temperatures. Can I fry with olive oil? Olive oil is the fat that is most suitable for frying since it has the highest smoke point of all edible oils: it breaks down at 210° centigrade and remains stable at very high temperatures. The benefits of using olive oil are particularly notable when we fry at high temperatures, between 130 and 180° centigrade. At these temperatures, olive oil creates an outer layer on food that is fine, consistent, crisp and golden. It also prevents the food from absorbing more fat while allowing it to retain all of its succulence. This results in more appetizing food with its nutritional value intact. How should I store olive oil? Olive oil has the same enemies as wine: light, air and high temperatures. Therefore, it should be stored in a cool, dry place, away from light and heat. How do I choose an olive oil to go with a dish? As with gins, wines, cheeses and salts, personal taste should guide one to choose which olive oil goes with a particular dish. As general guidelines, lightly fruity olive oils are recommended for white fish, sauces such as mayonnaise, chicken, desserts and vegetables such as potatoes, carrots and leaf vegetables. Olive oils with an intense fruitiness are recommended for oily fish, vegetables such as broccoli, salads and red meats.