Frequently Asked Questions
COOKING WITH Olive Oil: Some like it hot
from The Sydney Morning Herald - May 2015 Sarah Berry
It's called Liquid gold, but can olive oil, like precious metal, handle the heat? a long standing myth is that you shouldn't cook with olive oil.
'Olive oil is very good for you but some olives have a very low smoke point, and produce small amounts of carinogens when heated' nutritionist Dr Glenys Jones told the Telegragh London recently, suggesting we should only use olive oil for salads and not cook with it.
So what is the truth?
The truth is simple, and its not!
Like many a good myth, the one that says we shouldn't cook with olive oil has only a drizzle of truth.
The basic rule is that not all olive oils are equal and the acidity of the oil determines the smoke point - which is when things get hairy and not so healthy. The fresher the olives are when crushed and turned into oil, the lower their acidity is. The lower the acidity the higher the tolerance to heat is. Also the better an olive oil tastes the fresher it is, the more nutrients it has which protects it when cooking, so the more heat it can handle. So a good unadulterated extra virgin olive oil (EVOO) will have low acidity that can tolerate heat as high as 200 -215 deg C. This is much higher than most of us use when frying or even roasting.
On the flip side, the older an olive is by the time it is crushed and turned into oil, the higher the acidity and the lower the smoke point.
And it is here we run into sticky territory. Many cheap imported EVOO's are not only old, but they are not necessary EVOO. Or not 100 % EVOO. Many imported oils labelled EVOO have been tested and found to be a refined version - or mixed with corn or palm oil (which has the same appearance as EVOO).
There is no regulation of EVOO labellingso it can be tricky to tell. In fact, the sheer number producers selling 'EVOO' when it's not EVOO, has lead to olive oil being called the world's most adulterated food. In one instance, the EVOO was in fact found to be lard!
Many Australian growers are part of the Australian Olive Association (AOA), which was created tp uphold standards and does regular randomised testing of products to ensure adherence. Oils certified by the AOA carry a triangle symbol on the bottle's label. When we are looking for authenic EVOO's, there are other ways to tell, says Cobram Estate's executive director Leandro Ravetti. He suggests looking for locally produced oil.'The closer the source, the shorter the time from tree to table' he says.
Look for a dark bottle (or a clear bottle ina box) as light deterioates any EVOO (it should be always be stored ina dark cool place) and check the harvest date of the oil is within 12 months of when buying it. Finally, apply the taste test. 'When you buy an EVOO, open the bottle and have a sip' Ravetti suggests. Good quality EVOO should feel fresh and leave no oily feelings in the mouth. If you don't like it, it is highly likelythat the oil is not really good. The other thing to consider, when choosing which oil to cook with, is how stable the oil is when heated for any length of time.
In this arena, extra virgin olive oil holds its own - in the top three behind virgin coconut oil and butter.
Ravetti says he happily deep fries and roasts using good olive oil.
This is good news, given the numerous studies where olive oil has been exposed to high heat for extended periods of time and found that it exhibited strong resistance to oxidative damage and kept most of its healthful prpoerties intact.
'Extra Virgin olive oil can do so many good things and it can really do nothing bad' says Brown University's Dr Mary Flynn, who has spent 20 years studing the potential health benefits of EVOO which include cardiovascular function, anti-inflammatory properties and weight loss.
Plus a drizzle of good oil improves the flavour and absorbtion of nutrients in salads and cooked vegetables. The more fat you eat with the carotenoids, the more you will absorb says Flynn.
What you need to know about olive oil
Extra Virgin, virgin, light or pure?
EVOO and VOO are two different kettles. EVOO is the best juice from the olive extracted with cold presses.
It is unrefined and no chemicals are used in the exytraction process: it is simply the juice of the olive fruit along with the abundant antioxidants it contains and low acidity.
'Virgin' oil has higher acidity and less nutrients and may well be lesser quality fresh olives. Both EVOO and VOO are cold pressed.
'Light',' lite' or 'pure' have? fewer kilojoules and are no more pure! They have been refined with heat and chemicals, resulting in an oil with no distinctive aroma, colour or taste. They are 'Light' on taste if you like.
Why does EVOO havea higher smoke point than virgin or refined 'light' olive oil?
' EVOO has higher smoke point than virgin olive oil because VOO typically has higher levels of free fatty acids - and those free fatty acids are more susceptible to thermal degradation' Ravetti explains.
'Refined' olive oil has a higher smoke point than EVOO because all the free fatty acids are chemically stripped with caustic soda during the refining process. Despite having a higher smoke point, Refined is less stable than EVOO during cooking because EVOO is rich in antioxidants that protect the oil against oxidation.