Things You'll Need
Nutcracker or hammer
Whether you're looking to add a healthy protein source to your diet, or you just would like to add a nutty flavor to a meal, walnuts are a handy type of nut to keep around the house. Due to the high fat content in walnuts, they can go bad when exposed to warm temperatures for an extended period of time. It's important to check any walnuts you may have kept in the pantry before using them to make sure they are fresh.
Look at the walnuts. If they look overly wrinkled, shriveled and rubbery, it's an indication of bad walnuts.
Touch the walnuts. Fresh shelled walnuts should be firm to the touch and should not feel moist. Soft and moist walnuts should be discarded.
Smell and take a small nibble of the walnuts. Fresh walnuts will smell nutty and have a sweet, nutty taste. Walnuts that smell like paint thinner and have a very bitter taste are rancid and need to be thrown away.
Touch the walnuts. Unshelled walnuts have a full and heavy feel to them. If the nutmeat inside rattles, it's an indication that the walnut is old and starting to dry out.
Examine the walnut shells. Discard any of the walnuts that have cracks or holes in their shell. The nutmeat inside will have been exposed to air and other elements, making it dry and inedible.
Test the nuts in water. If you picked the walnuts yourself, you need to check too make sure that insects such as maggots and walnut weevils did not get into the nuts. Place the nuts in a bucket of water. Nuts that sink to the bottom are good, nuts that float indicates insects have gotten to the nutmeat inside, which is why it is light enough to float. Discard any floating walnuts.
Always store walnuts in the refrigerator whether shelled or unshelled to ensure freshness. Shelled walnuts will stay fresh in the refrigerator for about a month, while unshelled walnuts can last up to six months.
If you want the walnuts to keep for longer, place them in a freezer bag and put it in the freezer. Walnuts can last in the freezer up to one year.
To open the shell of a walnut, use a nut cracker to crack the shell, or firmly hit the shell with a hammer to crack it open.