If you make your own pesto, you’ve probably been making it in a food processor. Right? That’s how I make it. Sometimes I use a hand blender when I can’t be bothered wrestling the processor from its cupboard. I also use the hand blender for salad dressings, sometimes. And I’ve noticed the bitterness in the salad dressings that I do make with the blender. Because we have six basil ‘bushes’ & we live in Indiana which means everything grows like a weed, I’ve been making pesto twice at week – at least. And only recently discovered what I’ve been doing wrong for YEARS!
I’m going out on a limb here & assuming you’re making pesto with extra virgin olive oil. That’s the norm. I also use extra virgin olive oil when I make hommus & other dips. There was always an underlying bitterness I just couldn’t put my finger on. Where did it come from? Turns out, extra virgin olive oil is super sensitive to mechanical agitation – as in a blender or a food processor.
How have I not known this? Okay, I’m going to get a wee bit technical here & tell you why, assuming, like me, you didn’t know this: olive oil contains a high percentage of a molecular compound called ‘polyphenols’ (polyphenols are responsible for olive oil’s reputation as being so good for us as these are thought to prevent some cancers/be cancer fighting). These polyphenols are coated in a fatty acid & these fatty acids prevent polyphenols being dispersed in a liquid environment. But, use a blender or a food processor to create an emulsion – pesto, salad dressing, mayonnaise & such, & these polyphenols are broken-up & distributed into the emulsion so their bitterness becomes apparent. Leading to whatever it is you’re making, such as pesto to become bitter. Fascinating stuff right?
What you’re left with is something that was going to be really good, ruined because of the bitterness. I do realise some of us have more disconcerting taste buds than others. And many I’m sure just assumed that’s just how the recipe was meant to taste, not understanding the science behind it. And why would you? I studied food science & I didn’t know this. There’s also a lot of guff on the internet about it but only one explanation is factual. I often don’t trust many sources, but the industrious people over at America’s Test Kitchen have tested it & proven it to be factual.
Traditionally, pesto was/is made with a mortar and pestle (hence the name meaning ‘to crush’). Basil, garlic, Parmigiana Reggiano (Parmesan cheese) and pine nuts were pulverized into a course paste & the olive oil stirred in at the end. Now I love a good mortar pestle as much as the next person & I’ve read some people think pesto tastes better being made this way (they would if they didn’t know about polyphenols & had been making it in the food processor) but, it takes much longer to make using a mortar & pestle.
Because I’ve been making pesto so often the last month & armed with the knowledge about olive oil & food processors, I think I’ve come up with a really good pesto method that takes mere minutes & is excellent. A little canola oil in the food processor with the other ingredients. Then processed until just finely chopped, no over-processing you want the little bits, not a paste, then stir the olive oil in at the end. It’s all in the recipe below. Try it & let me know what you think. Oh, I almost forgot – I’ve also tested this recipe using toasted pine nuts & raw pine nuts – no difference. This was good news because I’m terrible about burning pine nuts when I roast then. Raw pine nuts also eliminates a step & reduces the time. A good Parmesan is key. It’s all in the recipe below, you’ll have to make it & let me know what how it turned out. Until next time, I’ve heading out to pick some more basil. Cheers, Lovoni
PINTERST PESTO PIC TO SHARE
- 2 cups packed fresh basil leaves
- 1/2 cup pine nuts
- 1/2 cup finely grated, Parmesan cheese (Parmigiano Reggiano – use the good stuff)
- 2 garlic cloves, peeled
- 2 Tbsp canola or avocado oil
- pinch salt & freshly ground pepper
- 1/4 to 1/3 cup olive oil, plus about 1 tablespoon extra
- Put basil, pine nuts, cheese, garlic, canola oil, salt and pepper into a food processor bowl and process until finely chopped; do not over process, - you don’t want the mixture to become a thick paste.
- Scrape mixture into a small bowl. Stir in the olive oil a tablespoon at a time until the oil is well incorporated & desired consistency.
- Spoon pesto into a small container (the less empty space above the pesto the better). Drizzle the extra tablespoon of oil over the top. Makes about 3/4 cup.
- Make ahead: The pesto can be made 3 days ahead and stored in an airtight container in the fridge.
- Serving suggestion: Add the pesto to pasta, meatballs, soups, stews, casseroles, roasted veggies, salad dressings…
I didn’t know blending pesto was why it was bitter either, and I’ve been making it for 30 years. I always thought it was the pine nuts fault or just bad olive oil. Thanks Lovoni!
I assumed it was the ingredients too. I really noticed in a ginger dressing I made weeks ago & so I started doing some snooping & discovered the real reason why. I wasn’t convinced though until I made it the way I suggested 3 times all with excellent results. Of course the traditional method is using a mortar & pestle but that’s quite a bit more time consuming, squishing all the pine nuts.