An Italian Chef Taught Me the Surprising Secret to Keeping Pesto Green
Right after I graduated from college, I hopped on the first flight to Florence, Italy, and spent the summer interning on an organic farm in the Tuscan hills. (Yes, it was as idyllic as it sounds.) I was in no rush to fly back to the U.S. after completing the program, so in an effort to stick around, I got a job at a tiny family-run trattoria.
The short version of a long story is I had to return home after about a week due to visa troubles, but I didn’t get on that plane empty-handed. Before I left, I spent a few days in the kitchen writing down as many tips, tricks, and recipes as I possibly could. I learned how to make ultra-tender fresh pasta dough, the creamiest mushroom ragù, and, my very favorite: the greenest, most vibrant pesto. There are plenty of tips out there that claim to help you hang onto the color, from blanching the basil leaves to adding a bit of lemon juice, but the chef I was learning from had another trick: an ice cube.
An Ice Cube Is the Key to Greener Pesto
While making pesto in a mortar and pestle is the most traditional approach, even many Italians have adopted the convenience of making it in a food processor, including the chef I worked with. He also skipped another classic part of the pesto process: blanching the basil, which involves tossing the leaves into a pot of boiling water, quickly transferring them to an ice bath, and squeezing the leaves dry before blending the pesto. Instead, he dropped an ice cube into the bowl of the food processor when pulsing the basil, which shocks the herbs and prevents them from browning.
Try this trick on our favorite pesto recipe: How To Make Perfect Pesto Every Time
You can do this with just about any pesto you make, including those made with other herbs and greens, such as parsley, mint, or arugula. The ice cube will rattle in the food processor at first, but will quickly melt and break down as you pulse the pesto. If there are any icy bits left, they will dissolve when you blend in the olive oil. The result is verdant green pesto without any fussy techniques or extra steps.