
This week I learned something new. I’ve attempted to make chimichurri, or other olive oil based sauces in the past but they are always so dang bitter. When trying to make my own mayo, I followed all the instructions. I used a “light” olive oil. I followed the recipe and ingredients to a T. Still bitter. I could not figure it out. I just assumed it was because I was using Costco olive oil.
But this week I wanted to give it another shot. I really wanted to make a spicy chimichurri so I started looking up other recipes to figure out how to make it work. That’s when I discovered that it wasn’t my fault, or even Costco’s. It was my blender! Cook’s Illustrated has an article that better explains why this happens.
Extra-virgin olive oil contains bitter-tasting compounds called polyphenols that are normally coated by fatty acids, which prevent them from dispersing in the presence of liquid. When olive oil is broken into droplets in an emulsion, the polyphenols get squeezed out and will disperse in any liquid in the mix, so that their flavor becomes evident. The blades of a food processor break olive oil into much smaller droplets than those created from whisking. The smaller the droplets, the more polyphenols that break free and disperse, and the more bitter an emulsion will taste. (Note: In recipes such as pesto, which contain lots of other robust flavors from herbs, nuts, and cheese, we found that any bitter taste went unnoticed.)
Testing Olive Oil’s Bitter End, Cook’s Illustrated
Roasted Jalapeno Chimichurri
So now that I know this, I changed how I made my Roasted Jalapeno Chimichurri. I ended up using a food chopper for the parsley, onion, and garlic. Then I whisked in the oil and vinegar. And guess what? IT WASN’T bitter! I felt like such a pro. Give the recipe a try and let me know how it goes!

Roasted Jalapeño Chimichurri
Equipment
- Food processor or chopper (optional)
Ingredients
- 1 bunch flat leaf Italian parsley
- 3-4 cloves garlic
- 1/4 red onion
- 1/4 cup red wine vinegar
- 1 1/2 tsp dried oregano
- 1-2 roasted jalapeño peeled and seeds removed
- 3/4 cup olive oil
- 1/2 tsp salt
Instructions
- Roast the jalapeños.
- Put the peppers on a baking sheet or an oven-safe skillet that can handle high heat, like cast iron. Stick the pan under the broiler until the entire pepper is charred, rotating as needed. This usually takes 5-7 minutes.
- Once the pepper is completely charred, remove from the oven and place in a food storage bag. You can use a plastic or paper bag. Let it steam in the bag while it cools.
- Once the pepper is cool enough to handle, the skin should easily peel off. Remove all the skin, the stem and the seeds.
- Finely chop the roasted jalapeño.
- Make the Chimichurri
- In a food processor or chopper add parsley, garlic, and red onion. Chop until everything is minced and combined.
- Transfer the chopped ingredients to a bowl and add vinegar, oil, oregano, and salt. Whisk together.
- Add in diced roasted jalapeño and stir.
- Let the Chimichurri sit for at least 30 minutes before using to allow all the flavors to combine.
- Enjoy poured over pretty much anything! My favorite currently is air fryer chicken wings!
Find more flavorful condiments HERE.