Bright green pesto is a beautiful thing. Brown pesto, not so much. Pesto turns brown when it comes in contact with oxygen, which gives it that unappealing gnarly look, and it doesn’t take more than a few minutes, which sucks. As a side effect, the oxidation mutes the bright licorice-like flavor of the basil that you picked right out of your backyard, and suddenly all that effort feels like it belongs in the garbage can. If you want to avoid sad brown pesto, there’s one quick thing you can do to avoid disappointment—and this applies to any leafy green you’re planning on using for the delicious sauce.
Blanch your basil leaves for fresh pesto
The solution to keeping your pesto green for longer is super simple. Blanch those leafy greens! Basil, arugula, spinach, whatever you pick, all it takes is a dunk. Boil some water and briefly (and I mean briefly, no longer than 30 seconds) dunk the greens into the hot water and then right into an ice bath. The ice bath is important because if you let the vegetables keep cooking, they’ll just wilt into a soft mess. That quick romp in the hot water will obliterate the enzymes that cause browning, and you’re all set. Then all you need to do is to continue on with your preferred recipe. Your pesto will stay green for longer and you won’t be sad.
How to store your pesto
Remember, you want to keep that delicious sauce away from oxygen, so pour a thin layer of olive oil (or whatever oil you were using for the pesto) on top. That’ll keep the air from touching the pesto directly, and it’ll stay good for longer that way. This also goes for if you’re freezing it as well. And of course, don’t forget to keep it in an airtight container, to keep that pesky oxygen out. But don’t forget to keep breathing, that’s when oxygen is your friend. Now go make some pesto, everyone. It’s easy and delicious.