As with other vegetables, a potato needs to be properly washed before it can be prepared and eaten — think about all the places it has been and all the people who have handled it as it made its way from the field to the market.
But there are few important tidbits you should keep in mind not only when you are cleaning your potato but also before and after, notably when you are buying it and when you are storing it.
Selecting a Good Potato
Although a few people tend to think of potatoes as a starch like rice or pasta, they are categorically a vegetable, and the Network for a Healthy California explains that they are a great source of vitamin C, vitamin B6, potassium and niacin. When you're picking out potatoes at the grocery store or farmers market, go for potatoes that are firm and have a smooth skin. You want to avoid potatoes that are shriveled, bruised, sprouted or green.
However, if you get home and realize that you have selected a potato with one of these unwanted qualities, you don't have to discard the whole potato. Per the advice of North Dakota State University, those green spots are simply due to chlorophyll. You should not eat them, but you can easily cut away the parts that are green and discard them. Same with any parts of the potato that have sprouted.
Washing Your Potato
Before you wash your potatoes or other vegetables, the Food and Drug Administration recommends washing your hands for 20 seconds with soap and warm water. Rinse your vegetables before you peel or chop them so that your knife doesn't transfer dirt or bacteria from the outside of the potato to the inside. Be sure to cut away any bruised or damaged places where dirt could get trapped and linger.
In most instances, according to the USDA, it is sufficient to rinse the potato under cold running tap water to remove any dirt or contaminants. You shouldn't use any detergents or soap, as these could leave a residue that you don't want to ingest. As the USDA points out, vegetable washes have not been approved by the Food and Drug Administration. You can, however, use a brush to scrub the potato.
Colorado State University Extension emphasizes that the running water should be no more than 10 degrees Fahrenheit colder than your produce, and if you opt to soak the potatoes instead of rinsing them, you should do so in a clean bowl rather than your sink because your drain could harbor bacteria.
It's important that you wash your potatoes right before you cook them. If you wash them and don't use them right away, any leftover moisture could promote spoilage while they're in storage, according to North Dakota State University. If you are not using your potatoes right away, store them unwashed between 45 and 50 degrees F. They will keep for several weeks. Don't store them in the refrigerator because this will change their starch compounds to sugar.
It's worth noting that while washing produce is important, food safety problems regarding potatoes are more frequently associated with improper cooling. Keep cooked potatoes above 140 degrees F and do not leave them at room temperature for more than two hours. If you have leftovers, promptly store them in the refrigerator at 40 degrees F and use them within three days.