We use oils in cooking for many different reasons, most commonly to prevent things from sticking to other things when heating them; we also use them for flavour and to change the texture of food. Each type of oil is used for a different purpose, here is a little run down of what oil is used for what…
Olive oil
– this is basically the king of the oil world and is extraordinarily tasty, is a monounsaturated oil (ask your science friends), is high in antioxidants and is pretty good for you on the whole, especially if you replace the saturated fats in your diet with it. Good olive oil is cholesterol free. Olive oil is not particularly suited for cooking as compared to most other oils; the ‘smoke point’ at which the oil begins to smoke and catch fire) is relatively low. By heating the oil, even before it reaches the smoke point, you can significantly change the flavour of the oil. While I like some of the New Zealand olive oils such as The Village Press on the market for value and quality I would recommend a good Spanish brand such as Borges. Beware of ‘light’ olive oils, they are an ingenious marketing plan – there is nothing light about them other than the colour, flavour and nutritional value. All oils are 100% fat and with light olive oil you are just missing out on all the good stuff. Good olive oil is translucent between bright, golden yellow and deep green in colour and has a fruity, peppery taste which is more vibrant in youth. Use to dress salads (just a jot of olive oil and a squeeze of lemon will do), in pasta, as a dip for bread, or as a flavouring on dishes just before they are served – carrot and olive oil soup is pretty flash.
Cooking oil
– because of my rant about the joys of olive oil I don’t really have space to address cooking oils one by one. If you buy the standard “salad and cooking” oil from the supermarket it will be a blend of two or more of these oils. All of them have a relatively high smoking point which means they are perfect for frying. No good for salads but you can retrofit your car to run on them.
Peanut
– made from peanuts and probably not in your “salad and cooking” oil because too many people are allergic to it, survival of the fittest I say!
Cottonseed
– this is most commonly used in the production of things like potato chips and in its un-hydrogenated form is not too bad. But in its hydrogenated form (created by adding hydrogen which is what they do to make potato chips) it becomes a trans-fat which (or so say the experts) is bad.
Canola
– strangely enough there is no such thing as a ‘canola’ plant, which kind of weirds me out; ‘canola’ is the brand name for Canadian Oil and is usually a genetically modified stain of rapeseed oil. According to Wikipedia, the Canola Council of Canada states it “is completely safe and is the healthiest of all commonly used cooking oils”. They would, wouldn’t they!
Rice bran
– this is the new kid on the block because it has an incredibly high smoking point (254 degrees) so, that means you can make some really crispy chips.
Nut oils
– aside from peanut oil, which I have covered, there are a whole range of nut oils which are used to impart their particular nutty flavour to food.
Coconut and Palm oil
– While being perfect for taming a frizzy hair day these two oils do not make good eating as they are particularly bad for your heart. They are most often (these days anyway) found as flavourings in budget brand packs of instant noodles. Both can be used as biofuels.
Flavoured oils
– Again, just for flavour, and boy there is a huge variety (and even bigger variety in quality). The most serious flavoured oils (such as porcini and truffle) should come in a relatively neutral base oil like canola or sunflower. Beware of flavoured olive oils because olive oil has its own distinct flavour. Do you want lemon flavoured olive oil? No (and punch the person who is telling you that you do)! A jot of oil and a squeeze of lemon will suffice. Better yet, make your own.