Keep Pesto From Browning With One Kitchen Staple

It's that time of year: You're harvesting a bumper crop of fresh basil and wondering what to do with it. One of the tastiest ways to use basil is by making pesto. This very green paste — used as a type of sauce, or even in some cases a condiment — is made from fresh basil leaves, garlic, pine nuts, olive oil, salt, and parmesan cheese. Anyone who has endeavored to make and store pesto has likely seen it go from vibrant summery green to middle-of-the-winter brown. So how do you keep that bright leafy color intact so that your pesto can spruce up your meal on a dark winter night? 

There's a simple answer. It only takes a squeeze of lemon juice to prevent your harvest from looking more like mud than a garden. Adding a bit of freshly squeezed lemon juice into the mix also gives the sauce a bit of an acidic tang, which in many cases is definitely welcome. A number of recipes also recommend toasting pine nuts (or any other nuts you might use) before adding them to the food processor with the other ingredients to bring out their flavor. This nuttiness complements the lemon perfectly.

Exposing basil leaves to extreme cold can also prevent browning. Prep your pesto as you normally would in your food processor, but add a couple of ice cubes to the mix before you begin pulsing. The browning is halted because the intense cold slows the oxidation process that turns those green leaves brown. Quickly blanching then tossing basil leaves in an ice bath will have a similar effect. Keep in mind, these methods slow the oxidizing reaction but don't totally stop it. But this is a good option if you aren't keen on lemon juice's flavor.

You can also freeze pesto in an ice cube tray to keep it super fresh in the winter. When you want to enjoy a summer's bounty, just toss a cube with some hot pasta and a little of the starchy pasta water, and presto: pesto pasta! Because garlic's taste can deteriorate when frozen, you can also opt to freeze a simple mixture of processed basil leaves and olive oil in a glass jar. Simply defrost, then make pesto as normal with the other traditional ingredients.