What's in a name: Unmasking olive oil, from virgin to cold pressed
Posted by Jane De Graaff on August 08, 2011.
Food Guru looks at the different grades of olive oil.
So when faced with such a huge variety, and covering everything from cold pressed to extra virgin, what are the most important aspects for choosing a top quality olive oil? Is the grade of oil important and what do the different names mean anyway?
For Bruce Eglington, founder of Pukara Estate, the definition of quality olive oil is simple.
“Freshness and flavour are the key points.” He says, pointing out that Pukara Estate only produces Extra Virgin olive oil.
“Primarily you need to look for freshness. Get the latest seasons you can. Harvest time varies around Australia, but for example in the Hunter we harvest in April / May. The oils need to settle before bottling so new seasons oils are normally available in July/August.”
Olive oil is the pressed oil of the olive fruit, which is one of the most widely grown temperate fruit crops in the world. Around 90% of the total harvest is destined for olive oil production, and Andalusia in Spain is the world’s principal olive producing region. It’s worth pointing out that given the different varieties of olive grown the world over, the resulting olive oils have a huge variety of flavours.
Testing out olive oils for different flavour profiles can be a lot of fun, but it’s worth knowing a little bit about what you’re looking for when you dive in.
If you’ve ever eaten an olive straight from the tree, you will have experienced that nasty, astringent bitterness caused by a particular glucoside in the fruits. Happily this component separates out naturally in the oil making process, leaving a rich, creamy oil.
Traditionally the fruits are gathered by shaking or raking tree branches by hand to dislodge the ripest fruit. But more commonly today mechanical tree shakers are part of this process. Fruit for oil must be gathered with minimal damage and taken for pressing as close to harvesting as possible to avoid oxidation, which lowers the quality of the finished product. Olives are then washed and any leaves, twigs and other refuse removed before they are taken to press where they are crushed to a paste known as pomace. Methods of pressing vary from traditional stone crushing-presses with woven filters, to modern centrifugal separation, but whatever the method, the best oils are made when the flesh is crushed with minimal heating or breaking of the pits. Once the oil is separated from the fruit and water paste you are left with the olive oil.
So what’s in a name?
Virgin: Typically Virgin olive oil is taken to mean oil from the first pressing of the olives. By American standards it should then be ‘suitable for human consumption without further processing.’ In more detail, Virgin oil (as defined by the International Olive Oil Council, Madrid) is governed by rules that cover the conditions, methods and even thermal conditions in which the olives are harvested and treated to make the oil. These stipulations protect the final product from unnecessary alterations to the final structure of the oil- resulting in the purest possible product.
Extra Virgin: is an additional category usually applied to olive oils and should refer to the lower acidity in these oils, which creates particular and desirable flavour profiles.
Cold Pressed: is the first pressing of the fruits. It is referred to as cold as the fruit left over after this press can be further treated with heat to release additional oils of a lower grade and lesser flavour profile. Cold pressed oils are released purely through the pressing process and have not been altered by additional processes, leaving flavours fresh, vibrant and distinctive.
Infused: Any olive oil that has had a complimentary flavour enhancer infused into it. This is usually done by immersing an extra ingredient into the olive oil (lemon, garlic, chilli) for an extended period of time to let the additional flavour mix into the olive oil. It can be ideal for making vinaigrettes, salad dressings or marinades for meats. It’s always worth checking that these oils have not been flavoured with artificial flavours and enhancers.
Olive Oil: is a lesser grade of oil that is made by further treating the fruit after first press oil has been removed. By using heat or other chemical processes additional oils can be released. These oils are then blended with virgin oil to create commercial oils with less distinct flavour profiles. Whilst less impressive in flavour, these oils are none the less stable oils that can be very useful in cooking, particularly where large quantities of oil with subtler flavours are required.
Olive oil standards in Australia have recently been revised to make labelling clearer and less misleading. Terms such as extra virgin have been standardised and country of origin has become clearer. So, having unravelled all that, are there any final tips for selecting the right oil for home use?“Flavours vary according to variety, place, season [and] pressing.” Says Eglington, so perhaps the best thing to do is to be adventurous and get in there and give them all a taste!