Can you cook with olive oil?
Some of the questions that we often get asked are - Can you cook with olive oil? (YES!) Isn’t that bad for you? (NO!) Which fats are best to cook with? (Extra virgin olive oil!)
In the world of nutrition, specialist and public opinion waxes and wanes on subjects such as this. However, we would like to settle things once and for all, and to back it up with some scientific evidence.
Extra virgin olive oil (EVOO) is a delicious cooking medium, full of flavour, the fats in there are good for you, and the other “purities” even better. EVOO is a stable oil that can be heated to relatively high temperatures, without impairing flavour and health.
Olive groves at Fonteta olive farm
One of the most important defining features of Mediterranean cooking for us, is the prevalent use of Extra Virgin Olive Oil (EVOO). It is used liberally and generously for frying, braising, roasting, in cakes and breads, for dressing salads, and emulsified in soups and sauces.
Thankfully, EVOO also happens to be very good for us, good for your bones and skin, as well as your heart and mind, and is one of the primary reasons that the people of the Mediterranean are renowned for their long and healthy life expectancies.
Finishing a Vegetable Briami with a final drizzle of glossy EVOO.
I remember as a young chef at the age of 18 I landed my first proper job, working on a remote Greek island at a beautiful restaurant in a Windmill. I was taken for a Greek take on a fried English breakfast after a rather big first night out on the island, when I was feeling more than a little worse for wear. I peeked through the slither of a door to check out what the chefs were doing in the kitchen, and saw them with frying pans cooking eggs and what they referred to as bacon. Those eggs were literally swimming in a pool of golden green oil, and the chef was pouring in even more extra virgin olive oil in glugs from a 5 litre container. I was unsure of it at the time, and to be frank, I still am, he didn’t need to use THAT much olive oil, but those eggs were delicious, and they really sorted me out. That was my introduction to the Mediterranean obsession with the juicy fats of the humble but sacred olive.
It is important to know that olive oil and extra virgin olive oil are two very different animals. Extra virgin olive oil is cold pressed straight from the mill, whereas olive oil can be extracted and processed using heat and chemicals, giving a higher yield, but a lower quality oil in terms of flavour and nutritional benefits.
The range of desirable flavours in olive oil, and the undesirable at the bottom.
Many people think that processed olive oil is better for cooking with. Usually based on the idea that there are more impurities in EVOO, and that those can burn at lower temperatures and lead to bad flavours and adverse health effects. This is not the case! I think ‘impurities’ is the wrong word to describe the complex flavour compounds and desirable antioxidant polyphenols found in EVOO. They are better termed ‘purities’. The processing of refined olive oil using heat and chemicals gives a greater yield and an oil with a longer shelf life, however, it takes these purities out, and also adds undesirable polar compounds, trans fats, and free fatty acids.
A 2018 Australian study heated different oils to high temperatures and studied the release of polar compounds and free fatty acids, the two key negative by-products of heating oil, that are known to be bad for health. They found that “EVOO has demonstrated to be the most stable oil when heated, followed closely by coconut oil and other virgin oils such as avocado and high oleic acid seed oils.”. Although EVOO had a lower smoke point than other oils (200°C), this was not actually an accurate sign of what was going on in the oil, they state that it is the high oxidative stability that helps to keep the oil clean and safe.
Cooking is about the careful use of temperature, among other techniques, to elevate, combine and transform ingredients into pleasurable dishes.
The actions of browning, searing, charring and frying are really important for developing good flavour in food. This browning happens between 140-165°C. Water boils at 100°C, therefore we need other mediums to help us to get to higher temperatures. That is where oils come in, which can reach much higher temperatures, and that is why it is so useful in cooking.
Burning of ingredients starts to happen around 175°C. Although an oven, a pan, or a fryer can be at 180°C, 200°C, or even 220°C, often the food will not reach a temperature that is high enough to burn. The food itself, particularly the water inside of it helps to keep the temperature down.
EVOO has a smoke point of 200°C. You never really want any oils to reach a temperature that high. Whenever frying or deep frying with oil, it is best to keep the temperature below 180°C, and if you do deep fry, make sure to change the oil regularly.
Award winning olive oil at Fontclara olive farm
On our retreats we take people to an exceptional olive oil farm called Fontclara, owned by an Italian man called Roland Zanotelli, who fell in love with the Emporda and the Costa Brava and built a wonderful life there amongst the olive groves. Their tours show you the trees, the different varieties of olives that are growing there, talk you through the picking and pressing process, which they take very seriously, and give you a tasting of their different olive oils, paired with different dishes. I found it fascinating to learn how to taste olive oil, much like learning to taste wine or coffee, there is an art to observing the aromas, the colours, the textures and the flavours. I like the idea of employing different olive oils in different situations: a balanced fruity oil like an arbequina or a kalamata makes a good standard oil, their bitter and peppery Argudell oil paired particularly well with the chocolate dessert, and their herbal Piqual is excellent paired with fish.
Learning to taste olive oil at Fontclara
Having an arsenal of interesting olive oils in your kitchen is useful when cooking Mediterranean food. However, don’t buy too much, and make sure that you store it properly. Good extra virgin olive oil will last for a maximum of 18 months. To keep it from going rancid, make sure to store it away from the sun and in a cool place. Use EVOO liberally when cooking, and particularly for finishing dishes to add freshness. Use Extra Virgin Olive Oil as a replacement for butter where you can, on bread, and in cakes, and it will significantly improve your health. This is one of the most important contributions of the Mediterranean diet.
Old gnarly olive trees at Torre Ronsat.
For further reading and listening:
This podcast from ZOE Science & Nutrition with Elizabeth Berger and Prof. Tim Spector gives some other great EVOO tips and info.
This is a link to the 2018 Acta Scientific Nutritional Health journal research piece studying the effect of heating on different types of oil.