Why Nuts Have a Short Shelf Life

Nuts are high in unsaturated fats. These fats are sensitive to outside elements such as light, oxygen, and heat, causing them to break down and spoil quickly. Depending on the humidity level, the form of the nut (whether it’s whole, chopped, raw, roasted, etc.), and the packaging or storage method, spoilage can happen within a few months — sometimes even before the “best by” date on the bag.

So, how can you tell if your nuts have gone bad? First, do a visual inspection for mold. Next, perform a smell test: if the nuts are rancid, they’ll have a sour smell, or they might just smell “off.” They will also feel soft to the touch, and (if you do eat one) they will have a bitter or sour flavor.

How To Store Nuts the Right Way

To keep nuts fresher for longer, store them in the fridge. The cold temperature keeps the unsaturated fats from breaking down too quickly. If you tend to purchase nuts in large quantities (for example, on your Costco runs), store any nuts you aren’t immediately going to eat in the freezer. The extremely cold temperatures will extend their shelf life even further. When you’re ready to eat them, just move them to the fridge for a couple of hours to thaw.

Whether you use the fridge or freezer, always store nuts in airtight containers, not the bags they came in. An airtight glass container or a plastic freezer bag with the air squeezed out works well in either scenario. Limiting the nuts’ exposure to oxygen is key to preventing oxidation and spoilage.

How long your nuts will last in the fridge depends on their unsaturated fat levels. However, when stored properly in the fridge, most nuts will last for at least six months, with some types, such as almonds and pistachios, lasting up to a year.

Instant Mash for Thicker Soup

Starches thicken soups well because, in hot water, they make a gel that traps water molecules, acting as a large, nearly invisible sponge. Purified starches, including cornstarch, arrowroot, and even potato starch (a staple of gluten-free baking), are powerful and fast-acting because everything that is not starch has been removed. Flour is different, though; since it contains protein and other materials along with the starch, it takes longer for its thickening power to develop, which is why you need to use more of it.

Instant mashed potatoes are not a purified starch, either. They are the whole potato in a cooked-and-dried form. Similar to flour, they will leave a soup, stew, or sauce opaque, rather than clear. Despite that limitation, they are a very useful thickener. Because they are precooked, they thicken immediately, just like a purified starch. Plus, unlike those starches, they won’t clump when added directly to the pot.

Perfect for Last-Minute Thickening

You can make a really quick potato soup by simply stirring some instant mashed potatoes into a cup of microwaved chicken or vegetable broth and seasoning it to taste. But the real value of instant potatoes is when you need a last-minute thickener because the soup isn’t coming together as it should. If you add more cornstarch, you risk making the soup gummy. Adding flour works, but then you need extra cooking time to get rid of that raw-flour flavor.

With instant potatoes, you don’t have to worry about either of those downsides. Just shake them in as you stir until the soup is thick enough. No fuss, no muss, no bother. An alternative that works nearly as well is a “quick-mixing” or “gravy” flour, such as Gold Medal’s Wondra and its competitors. Since it’s also precooked, it’s quick to use and resists clumping almost as well as the spuds.