Lemon Is The Key Ingredient To Keep Pesto Looking Vibrant

Pesto's versatility and ease make it a popular sauce or spread for your pasta, grilled meats, vegetables, and sandwiches. Traditionally, ingredients like basil, pine nuts, parmesan cheese, garlic, and a little salt all go into a blender or food processor and are pulsed until they are velvety smooth, creamy, vibrant, and green. However, if you've ever noticed that your bright and fresh pesto starts to discolor not long after you've made it, don't fret because this issue can be easily reduced with the simple addition of a little lemon juice.

Whether you are making this sauce with basil, cilantro, or parsley, lush green pesto turning dark is an all too common occurrence caused by oxidation. As this sauce is being prepared and your green herb of choice is being chopped up, its cell walls are being damaged which results in enzymatic browning. Enter the lemon and its powerhouse of antioxidants, including both citric and ascorbic acid, which help minimize and inhibit oxidation in its tracks. But there is also a side benefit to adding a little lemon juice. 

Lemon juice also brightens up the taste of your pesto without drastically altering its flavor. Just 2 teaspoons of this citrus not only keep it looking fresh and green, but it also cuts through the rich taste of the parmesan and pine nuts, balancing the overall experience for your mouth. 

Lemon is not for everyone and if you aren't a fan of the taste of lemon in your pesto but don't want it to turn colors, you can blanch your green herby leaves. This added step will make your mint, basil, and any other herb greener, but be prepared for a less flavorful pesto. Using this technique can reduce the beautiful pungent, spicy, sweet, and minty nature of these herbs.

If you make too much pesto, using this lemon trick also allows you to store it in the fridge for up to a week before the color starts to turn. You can also freeze your pesto if you want to keep it for future use.