Don't throw away this flavorful (and free!) ingredient.
Planning on juicing that abundance of winter citrus sitting in your fridge? Well, if you want to take full advantage of the flavorful fruit, you should be zesting your oranges, lemons, limes, grapefruits and any other citrus fruits you have on hand before you juice them. After you wash them, use a Microplane ($13, amazon.com), to zest the fruits, being sure to zest just the colorful exterior and leave the bitter white pith behind.
The zest is where you'll find the highest concentration of the potent essential oils of the fruit—it has an extremely high amount of citrus flavor in a rather petit package. There are an abundance of uses for citrus zest that will make you happy you saved this culinary commodity.
First off, adding citrus zest to salt is a great way to season dishes. Likewise, you can do the same with sugar for your baking endeavors. In fact, if you're looking to add citrus flavor to baked goods, it's better to add zest than juice (the added liquid can mess with the ratios in your custard or souffle).
But don’t stop at salt and sugar. Just about every vinaigrette, aioli, compound butter, brine, glaze and sauce could benefit from an extra punch of citrus flavor. You can even add some to your ice cube trays to add some extra orange, lemon or lime flavor to your next cocktail—and a gorgeous speckled ice cube visual, to boot. If you're not planning on using it right away, store zest in zip-top bags in the freezer. The color will fade, but the flavor will stay strong for up to two weeks.