Mar 18 2009
The Bitter Truth About Olive Oil
Olive Oil and Balsamic Vinegar
Have you ever had homemade hummus turn out bitter? Have you whipped up your own batch of mayonnaise and found an unpleasant aftertaste? Or are you just confused about why I warned against putting olive oil in a blender for my harissa recipe?
The culprit behind these bizarre phenomena is extra-virgin olive oil, which is very sensitive to mechanical agitation. Upon one reader’s request, I set out to explain the unusual behavior of this common ingredient.
But getting to the bottom of this problem was not easy. The internet is teeming with false assumptions and unfounded hypotheses about why olive oil can become bitter when blended. Most people point their finger at the quality of the oil itself, accusing the chef of using a cheap brand that was bitter before they included it in their recipe. I knew this wasn’t true because it has happened to me several times, and I always use excellent olive oil.
Another common hypothesis is that “heat” caused by the friction of high-speed spinning blades makes the “delicate oils” in the olive oil turn bitter. This explanation makes even less sense, because as most of you know olive oil can be heated in a pan to several hundred degrees and does not burn or turn bitter. There is no way the oil gets hot enough to go rancid after a few seconds in a blender.
The only logical and (mostly) scientific explanation I found for the bitter olive oil phenomenon was from Cook’s Illustrated. I am inclined to trust this source because they essentially run their kitchen like a laboratory, which gives them major credibility points in my book. Also, their reason offers a plausible, mechanical explanation that does not depend upon the quality of the oil itself. I have not seen the data with my own eyes, however, and they do not cite their sources.
According to Cook’s Illustrated, extra-virgin olive oil is the only kind of oil susceptible to becoming bitter. Even pure olive oil can handle blending better than the extra-virgin kind. The reason is because extra-virgin olive oil contains a high percentage of molecular compounds called polyphenols (thought to be cancer-fighters), which are normally coated in fatty acids. Under standard conditions, the fatty acids in the oil prevent polyphenols from dispersing in an aqueous environment. This is because oil and water do not mix.
When these fat molecules are broken into droplets in an emulsion, however, the polyphenols are distributed into the solution and their bitter taste can become apparent. When the emulsion is only lightly blended, the bitterness is not perceptible. But a blender or food processor breaks the droplets down into smaller sizes, increasing polyphenol dispersal. These suspended polyphenols can ruin an otherwise delicious recipe.
The easiest way to avoid this problem is to use either pure olive oil or a different kind of oil altogether, such as canola or safflower oil. Alternatively, if you would like to keep the rich taste of extra-virgin olive oil you can hand whisk your emulsion rather than using a blender. Just be careful not to over work the mixture. You can also start your recipe by blending a small amount of stable oil (e.g. canola), then hand whisking your extra-virgin olive oil in at the end.
Have you ever had problems blending extra-virgin olive oil?
If you enjoyed this post, you might want to subscribe to Summer Tomato and follow me on Twitter!
Tags: bitter, blender, Cook's Illustrated, extra virgin olive oil, food processor, hand blender, hummus, mayonnaise, polyphenol
Print This
•
Loading ...
I just realized a few days ago that the olive oil I’ve been using the last year (infused with peppers) is actually sunflower oil.
Interesting. I have not tried to use EVOO in anything that required blending or emulsion. I recently have come across a no-soy mayo recipe from Mary Enig’s book/website Eat Fat Lost Fat and am tempted to try it (since I have not had mayo in years now!), but will have to reconsider using extra-virgin olive oil. Thanks for the tip!
Wow, great picture darya!! (I think I love every single one of them) And thanks for the informative post. I would have just as soon believed you without understanding, but I guess I love to know the “whys” too. Thanks!
Because of the versitility, tastiness, and health benefits I declare that Olive Oil is a superfood. Anyone agree/disagree?
I always wondered why that happened! Great post.
@doug
Sounds delicious
—–
@Erica
Glad I could help. It’s really, really bad to mess up. Ruins everything. Let us know how your experiment goes!
—–
@Katie
What would I do without your encouragement? Thanks!
—–
@Scott
LOL, you know how I feel about superfoods.
—–
@Travis
Me too! Luckily it is not that hard to avoid.
I LOVE your blog — so informative!
No i’ve never noticed a problem but I trust Cook’s. Good info!
I think this happens more often than we think. We were just served an olive oil at Buca di Beppo (hardly a temple of cuisine) that was so bitter it tasted like it had been sitting in a rusty can. Now, the oil wasn’t in a recipe, but you have to wonder if the blending process for it was a bit too rough!
Yikes, that oil was probably rancid. That is another way it an get too bitter.
I’m just suprised more people aren’t in an uprage about all the sub-par olive oil that goes around…..I wonder if there is a difference in the lipid profile of high vs low quality olive oil….my guess is yes. And yes I agree Scott, it is definately a superfood.
Love the pic, Darya. Is your olive oil really that green? Mine is always an orangy color.
The bitterness is a feature, not a bug! F’rinstance: McEvoy’s Olio Nuovo, which you can get in season at the Ferry Building, is polyphenolicious.
To be honest, I have always heard people say Olive Oil rules, guess everything does not come all good.
As soon as I saw the caption of Foodgawker, I knew I had to hop over here to find an explanation for one of my problems! I’ve blended EVOO in the blender before with no problems (like in a couple of salad dressings I make) but every single time I try to pulse my chimichurri in the food processor it gets SO nasty! I started googling stuff to find that EVOO could be the culprit, but never once did anyone say it was the actual *blending* that caused it, the explanation always pointed toward low quality EVOO or something. But I tried it with every brand out there and still no luck. I only put it in the blender because I like a super fine texture, but I guess I’ll have to attempt to get that with a knife. Good post- thanks!
Funny, when I make chimichurri, for some reason it always tastes better if I chop everything by hand rather than use a food processor. Not sure why. As far as the olive oil, good info, I’ll have to keep this in mind,
Great olive oil post. I haven’t noticed that it gets bitter, but I have noticed that when you put it in the food processor it loses some of it’s flavor. I always use a mortar and pestle to make things like pesto or anything with an expensive olive oil – for this and other reasons. What brand of olive oil do you like best? I’m big on Sicilian oils, but after my recent move to Berkeley, I’d really like to find a quality local one.
I like Stonehouse, but I’m a big fan of fruity oil. McEvoy is great if you like a little more bite. You can find both at the Ferry Building. You should come to the farmers market tomorow!
Hi Darya
Great post, photos and explanation! I never knew that extra virgin olive oil could be so sensitive when mixed with other ingredients. I and my husband produce our own 100% extra virgin, hand-picked olive oil “Ginestre 12″ from the Abruzzo region in Italy. We have 61 young olive trees and we are relative newcomers to olive oil production.
Nothing beats the flavour of virgin olive oil and I use it every day in all my cooking.
fantastic post! i’m new to your blog and becoming a big fan fast! thanks!
Awesome, thanks for dropping by! Let me know if you have any questions
I’m really glad I found this post! I have chickpeas soaking right now to make hummous for a party tomorrow, and I always use EVOO. I may use a bit of grapeseed to help it through food processer, than add the olive oil after it’s all done. I’ve never noticed the bitterness per se, but have always been surprised by how much salt I needed to add to make it taste okay.