Do Pine Nuts Go Bad?

So you decided to buy some pine nuts to make homemade pesto. And the pesto turned out pretty good, but you’re left with a big bag of pine nuts. Once you realized that going through the entire bag will take some time, you started to wonder: do pine nuts go bad?

Pine nuts, also known as pinoli (or pignoli) nuts or piñón, are often used to add a pleasant crunch to everyday dishes, snacks, and desserts. So what if you wanted to take advantage of a sale and bought too many bags of pine nuts? These nuts are quite expensive, so you definitely don’t want them to go to waste. The first thing you do in such a situation is probably to find out how to store them properly for the long term. The second thing is learning about their shelf life, so you know for how long you can keep them around.

In this article, I cover all of the above. We go through storage, shelf life, and going bad of pine nuts. If you’d like to learn more about that, read on.

Pine nuts
Image used under Creative Commons from Stuart Webster

How to Store Pine Nuts?

Just like other nuts such as cashews or pecans, pine nuts are loaded with plant oils. And oil is susceptible to going rancid. Because of that, you need to protect the seeds of pine from temperature changes, high temperature, moisture, and air. All of those have a say in the rancidification process, some more than others.

Since pine nuts are almost always sold shelled, unlike e.g. walnuts, there isn’t any barrier between the seed (nut) and the outside world. Thus you need to take care of creating that barrier. At least if you want your pesto to turn out tasty.

First of all, you need to store pine nuts in a cold temperature. Since they’re already shelled, it’s either the fridge or the freezer. If the nuts come in a sealed package, you can put them directly into the refrigerator. Once you open the packaging, make sure to transfer pine nuts to an airtight container or a freezer bag before refrigerating. A container with a good seal is necessary because it keeps any strong odors and moisture at bay. Of course, make sure it is sealed tightly at all time.

If you expect to store the nuts for more than a few months, the freezer is the way to go. The nuts need to be protected from the cold air, so even if they’re in the original, unopened package, you still need to either wrap it or put in a freezer bag or container.

Pine nuts in a jar
Image used under Creative Commons from jules

How Long Do Pine Nuts Last

Pine nuts should come with a best-by date on the package. Since the nuts are already shelled, they don’t retain freshness for all that long. And out-of-shell pine nuts definitely don’t keep as well as walnuts or even pecans. In short, you should expect that the best-by date will be probably only two or three months from the day you buy them. Of course, the nuts won’t go bad or rancid a day or two after that date, but over time the quality will degrade.

If you need to store pine nuts for a prolonged period, repack and freeze them.

Fridge Freezer
Pine nuts (unopened or opened) Best-by + 1 month Best-by + 3+ months

Please note that the estimates above are for best quality only.

How to Tell If Pine Nuts Have Gone Bad?

Like other nuts, unless you mishandle them in storage, they won’t go bad in a way they’re unsafe to eat for quite a long time. But as I already mentioned, they can go rancid. And while rancid nuts aren’t necessarily unsafe to eat, the taste is much worse.

The most obvious sign of rancid pine nuts is the aroma. If the nuts smell like used or rancid oil, they are definitely rancid. And you don’t want to make a pesto with rancid pine nuts. If the smell is only slightly altered, then probably some of the nuts are already rancid, and the rest is about to turn that way too. So it’s pretty much now or never if you still want to use these nuts. Another sign of rancidity is a bitter taste. So if you’re about to make a pesto with pine nuts that are sitting in the fridge for quite some time, eat a few nuts to find out if they’re good enough to use.