The most common way nuts go bad is by becoming rancid. This happens because they are stored for too long or in poor condition. Shelled walnuts can last up to 12 months, maintaining their freshness and quality. However, once the housing is removed, the life of the nut decreases significantly.
Walnuts have a fair shelf life, which lasts up to 3 months with the shells set at room temperature. When the shells are removed, the nuts oxidize much faster and only stay fresh for a couple of weeks. Expect shelled walnuts to last a year in the pantry and about 1 to 2 months past their expiration date. Once a package of nuts has been opened or the shell removed, it is best to refrigerate them immediately in a sealed container.
Nuts should have a fresh nutty scent, but if they seem to smell more like stale oil or cooking oil, the nuts have spoiled. To keep your nuts from going stale for as long as possible, you protect them from air, heat and light. Walnut shells naturally protect walnuts from some of these factors, increasing their shelf life, but shelled walnuts don't have a natural defense. Many experts suggest that to freeze shelled walnuts, use an airtight container to make them last longer.
Naturally, when you buy nuts that are still in the shell, they have an additional layer of protection against these harmful elements. Although shelled walnuts may be more practical, shelled walnuts include their protective barrier, which means you don't have to worry as much about your storage methods. However, one important thing to know about walnuts is that sometimes, when the kernels and the appearance of the nuts appear to be OK, they can still be inedible. Even if you store them well, you can expect the walnuts to last up to 2 weeks when you place them in the pantry.
While shelled walnuts require a lot more effort to prepare when it comes time to prepare your recipe, the positives outweigh the negatives. So, if you shake your shelled nut and hear the walnut moving inside it, it's time to throw it away. Food Keeper says the shelf life of walnuts is very limited, such as 2 to 4 weeks of storage for shelled and shelled walnuts. If you find that your nut shell has shrunk, warped, or dried out, you shouldn't even bother opening it, because in that case, the nut has gone stale.
So why do walnuts go rancid faster than other nuts? And how can you store them so they last longer? Keep reading for more information.