They might seem like tough you-know-whats, but walnuts are actually sensitive to heat and air exposure. To prevent spoilage, keep the nuts in their protective shells, place them in an airtight container, and store in the fridge for about a month. (If you like shelled nuts instead, choose the whole, not chopped, kind.) Not planning on eating them right away? Stash walnuts in the freezer for up to a year.
Some recipes call for rubbing off the papery exterior, but it's smart to keep this coating on. That's because many of the antioxidants are found in the skin.
Too-high heat can damage the heart-healthy fats in nuts, so proceed with caution if you love the taste of toasted walnuts. Keep your oven under 350°F and bake them for no more than 10 minutes. If you prefer to use your stove top, toast them in a skillet over medium-high heat for 3 to 5 minutes, stirring frequently. Cooking them at a higher temperature or for a longer period of time can break down the omega-3 fats.
A 1-oz. serving of walnuts is 0.25 cup, 7 whole nuts, or 14 halves. Eyeballing it? That's about the amount that fits into a cupped palm.
Walnuts are everything they're cracked up to be. Eating them often can help you …
Sources: Aida Mollenkamp, chef and author of Keys to the Kitchen; Wendy Bazilian, Dr.P.H, R.D., author of The SuperFoodsRx Diet; Rachel Begun, M.S., R.D., spokesperson for the Academy of Nutrition and Dietetics