Olive oil from Imperia in Liguria, Italy. (Photo credit: Wikipedia)
“You shouldn’t cook with olive oil.”
Well, isn’t that just an invitation to cook with olive oil?
Is olive oil really a ticking time bomb under cooking heat? The taste is divine and the liquidity super convenient. Do I need to feel remiss for blogging the recipes I cook and bake with olive oil?
I took a look.
(I’m talking about virgin or extra-virgin olive oil in this post. See here for help in differentiating types of olive oil. It can be overwhelming.)
Bottom line first: Baking and cooking at fairly short, typical kitchen temperatures minimally changes olive oil, but not enough to stress me out.
It’s no longer in my mind, “Can I cook with it?” but instead, “Which brand should I be cooking with?”
Most importantly with olive oil, you get what you start with.
Many (maybe most) olive oils are well-degraded before you ever open the bottle, and cooking only intensifies that. Start with good quality, fresh olive oil. If you don’t, you may as well catch it on fire. Oxidation at its finest! Opa!
Oh, yeah. And to get the full benefits of olive oil, make sure and use some uncooked every now and then (I opt for 2-3 times daily)! Since you get what you pay for and you want to get your nickel’s worth–lick the plate. Yum. A quality extra-virgin olive oil–it’s that good.
If you want a little more detail on the “can I cook with olive oil” question–keep reading. If you want a lot more, read the sources listed at the end.
Can I feel comfortable using olive oil for cooking and baking?
Yes. I can.
Doesn’t olive oil degrade with heat?
Yes. It does. And also with exposure to light and oxygen. In fact, there’s a good chance your store-bought olive oil is rancid before it has even gotten to you.
Ideally your olive oil would come in a glass or stainless steel container from a well-stored supply that was properly shipped and wouldn’t be sitting under bright fluorescent grocery lights.
Quotes below elaborate on what keeps olive oil from oxidizing.
“Pérez Cerezal et al. reported that olive oil stored in iron tanks can be oxidised rapidly if they are not coated internally with epoxy resins. They also compared the differences in oxidative deterioration between virgin olive oils stored in an iron tank and those stored in a polyesterglass fiber tank. After 10 months, the former had undergone a significant oxidative deterioration while the oxidation extent of the latter was as low as that found for the control oil stored in glass bottles at 4 °C.” (1)
Really? How do I know if Bertolli’s olive oil is stored in iron, epoxy resin-coated tanks? DO YOU KNOW? And to go on…
“In this respect, stainless steel is considered the most appropriate material for tanks in order to avoid the presence of detrimental factors during storage, i.e., light and metal, contamination. Additional protection with inert gas to decrease oxygen concentration would be the complementary measure to maintain a high oil stability. The influence of packing materials on olive oil stability was also studied in detail under different commercial conditions. As expected, results from long-term storage studies indicate that impermeability to air and protection from light increase the oil shelf life significantly.” (1)
And finally, are you that consumer?
“At present, virgin olive oil is usually commercialised in glass transparent bottles since consumers like to see the oil that they purchase. Consequently, the lack of protection from light is the predominant factor that can accelerate oxidation by catalysis of radical initiation or, in the presence of photosensitisers, by formation of singlet oxygen.” (1)
Okay, but you’re pretty sure you’re buying “FRESH pressed olive oil”, nearly off the tree! So it’s good when you pour it (you think)! What about cooking? Can you cook with it? Doesn’t it ruin it? Make it DANGEROUS?
Nah. It doesn’t magically form wicked trans fats or sorely picked on, probably unjustly, saturated fats. However, its beneficial compounds will degrade with cooking heat, just like when it sits next to your hot stove in a clear, plastic bottle on a sunny day. Just like it could in that iron vat mentioned above–perhaps long before it ever reached you. Way back in Italy or Spain.
I feel comfortable cooking and baking with olive oil at my typical ranges of about 300-400 degrees Fahrenheit (149-204 degrees Celsius). And my typical times of about 10-30 minutes.
Why? What makes me say that?
“Effects of Conventional Heating on the Stability of Major Olive Oil Phenolic Compounds by Tandem Mass Spectrometry and Isotope Dilution Assay” has a nice table (Table 1) looking at olive oil’s phenolic compounds’ breakdown at typical cooking temperatures. There are other components that make olive oil beneficial, but phenols are some of the most labile ones. I feel pretty comfortable that my usual 375 degree Fahrenheit (180 degrees Celsius), 20 minute roasting of vegetables does not allow enough time for much degradation of the beneficial compounds in olive oil.
Table 1 in the article (I couldn’t copy it and paste it. Sorry.) lists eight phenolic compounds. Three of the compounds get diminished by about 50% at 30 minutes of 338 degrees Fahrenheit, and the rest have fairly negligible deterioration.
So I figure I’m losing even less on my five-minute pancakes. If I could cool my jets to about 200 degrees Fahrenheit (90 degrees Celsius), I’d save about all of those glorified compounds! (2)
(To get your bearings, for nice, golden brown pancakes, I run my skillet at about 350 degrees Fahrenheit. Medium-low on my stove burner–but they all vary immensely!)
About nothing I cook with olive oil exceeds 375 degrees Fahrenheit (191 degrees Celsius) for longer than 20-30 minutes. So if I’m starting with a great oil, I shouldn’t be oxidizing the poor stuff beyond its beneficial use.
Last Asides:
- Mark’s Daily Apple has some studies quoted defending use of olive oil in typical kitchen cooking, but I could only pull up the abstracts: “Defending Olive Oil’s Reputation.”
- Smoke point of virgin olive oil is about 400 degrees Fahrenheit (204 degrees Celsius), but it will vary from brand to brand, year to year, location to location.
- I like to find a fresh, peppery extra-virgin olive oil for a needed robust flavor and a milder one for things like mayonnaise or baking. But if I’m out of one or the other, I just use what I have.
- I like coconut oil, which is great for cooking because it tolerates heat better than olive oil, but it gives me a yucky feeling in my head, let’s call it a headache for convenience sake. And some other untoward side effects. (Early on in GAPS, I couldn’t understand why I didn’t feel tops sometimes. I later linked it to liberal use of coconut oil.)
- Cloudy olive oil actually suggests an oil with more stability; oxidation occurs more slowly.
I really help this helped you! Have a great day (or night)!
Sources:
(1) Velasco et al. Oxidative Stability of Olive Oil. Eur. J. Lipid Sci. Technol. 2002; 104: 661–676
The HSD 