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When it comes to favorite foods, hardly any ingredient is as versatile and beloved as the potato. From chips and fries to mash and soup, potatoes are a staple in our diets, to the point we eat around 100 lbs of them every year. But for as many potatoes as we eat, potatoes are also infamous for hiding in our cabinets, sprouting in the darkness, until we pull them out and wonder, “Are these still any good?” We’ve all been there, halfway through dinner, with no time to run back to the store and less time to make a judgment call on the science experiment we just found in the cupboard.
To make the call on whether the potatoes are worthy of making the plate, it’s helpful to know just how to judge them. From soft spots to discoloration, some tell-tale signs of spoilage can spell food poisoning, mold toxicity, and more. It’s nothing to brush off as being overly cautious, either, as close to 13 people land in the hospital every year with potato-related illnesses. Knowing signs of spoilage and how to best handle and store potatoes to preserve freshness is a great way to ensure food safety and avoid potential health issues.
What is the Common Shelf Life of Potatoes?
Potatoes are a large staple due to their long shelf life. At around 50 degrees, potatoes can last 2-3 months when stored in a dark place. However, those same potatoes may only last 1-2 weeks in a warm, humid, brightly lit space. It is also important to note that sweet potatoes and late-season potatoes (potatoes with thicker skin) will last longer in ideal conditions than fingerling or baby potatoes and early-season potatoes (with thinner skin).
No matter what potato you store for later use, keep them in a cool, dry, dark place with plenty of ventilation. Potatoes that have been sprouting for too long are mushy, slimy, or have an odor should all be discarded due to signs of spoilage.
What Can Happen if You Eat a Bad Potato?
Feel like throwing caution to the wind? Better safe than sorry is the motto in this case. Let’s remember that potatoes do, after all, grow in the soil. And that soil contains all sorts of organisms that hitch a ride on the potato right into the bag and ultimately into our cupboards. We could wash all of our potatoes as soon as we bring them home, but doing so would shorten the shelf life further. More often than not, we will keep our potatoes unwashed until use, but it’s just this practice that we have to consider when deciding whether to consume those questionable spuds.
Food poisoning from bacteria causing botulism, listeria, e.coli, and salmonella have all been linked to potatoes. Most cases come from unwashed or improperly stored potatoes, which gives the bacteria a chance to thrive. Symptoms like nausea, vomiting, diarrhea, or cramping several hours to days after consuming a questionable potato are all signs of food poisoning, and cases lasting more than two days can lead to hospitalizations and, worst case scenarios, even death.
Though the most severe outcomes are unlikely, signs of gastrointestinal discomfort, such as bloating, gas, and abdominal pain, can indicate that your potatoes have gone bad. Potatoes are the leading cause of solanine poisoning, a toxin that forms when potatoes (usually ones left in a brightly lit area) turn green. While severe poisoning leading to hospitalization is rare, excessive consumption of questionable, aged, or greening potatoes can cause more minor symptoms of general discomfort.
6 Tell-Tale Signs Potatoes Are Bad
Telling a good potato from one that is past its prime doesn’t have to be a guessing game. When inspecting your potatoes, look for a few key signs of spoilage.
Mold Growth
Large fuzzy patches are an instant disqualifier but also look for divots, excess moisture, and patches of softness and discoloration, as these are signs of mold growth in your potato. When in doubt, throw it out.
General Softness
Potatoes are a firm tubor and should not be soft to the touch. If you can bend your potato, or if it is generally soft and caving in where touched, it is a sign of internal decay and should be discarded.
Discoloration
Dark spots and browning on your potato are likely signs of rot and potential bacterial growth. The moisture can allow bacteria to thrive if your potatoes have gotten wet. If your potato is not uniformly colored, discard it.
Foul Odors
Smell is an instant indicator of most potato quality. Raw potatoes shouldn’t have much discernable smell. If you smell musky or unpleasant odors on your potatoes, discard them immediately, as it is a sign of decomposition.
Sprouting
Potato eyes are a sign of aging, and while one or two across a whole bag of otherwise sturdy, fresh potatoes shouldn’t be cause for alarm, excessive sprouting indicates the potatoes have aged to the point that the quality has been diminished. This also means any lingering bacteria has been allowed to multiply, and these sprouting potatoes should be discarded.
Greening
While darker discoloration is typically a sign of rot, greening can signal your potatoes have developed a toxin known as solanine. While it is rare to consume enough solanine through green potatoes to get critically ill, consuming green potatoes can lead to more minor symptoms like headache and gastrointestinal discomfort.
How to Know If Mashed or Fried Potatoes Are Bad
If the potatoes have already been prepared and you are still questioning their freshness, there are ways to tell if your dish is safe to eat. Any foul, sour smells indicate that the food is spoiled, as is visible discoloration of the finished dish.
Textures that are mealy, slimy, gritty, or soggy and not typical of the cooked potato are also a sign that the potato dish in question should be discarded as spoiled. Sour or rancid tastes are also not typical for cooked potatoes, and any potato preparations with sour or rancid taste should be thrown out.
What is the Best Way to Store Potatoes?
A few basic rules should be followed to store potatoes optimally and preserve their freshness. First, store your potatoes in a cool, dark place. While a temperature around 50 is ideal, refrigeration is not a preferable storage method for potatoes, as it can alter their texture. Limited lighting is also important to prevent the development of the solanine toxin.
Second, your potatoes should be stored in a dry location and in a breathable bag. Allowing the air to circulate helps prevent moisture buildup, which can help keep bacteria from growing. Third, store your potatoes away from your onions. Though they are both dry storage items, onions omit a gas that can accelerate the sprouting of your potatoes, causing quicker spoilage.
Bottom Line
We love potatoes and can love them longer the better we store them and the better prepared we are to make the call on when to throw them out. Selecting fresh, firm, uniformly colored potatoes and storing them in a cool, dry place away from light (and onions) will give our potatoes the longest shelf life possible.
Any signs of excessive sprouting, softness, greening, or mold growth should be taken as spoilage warnings and tossed out. Foul smells and tastes from fresh or cooked potatoes also indicate that the potatoes shouldn’t be consumed. By knowing what to look for and what a sign of potential danger is, you’ll be best suited to continue home cooking safely!
