Around the holidays in the United States, you may hear the words yams and sweet potatoes used interchangeably in the kitchen. These words are usually to describe sweet dishes sometimes made with marshmallows, butter, and cinnamon. Although yams and sweet potatoes are separate vegetables, they have similarities as both are tubers of their respective plants; however, the yams vs sweet potatoes debate goes beyond appearances.
Are yams the same as sweet potatoes? The short answer is no. However, when visiting your local grocery store, if you aren’t sure what they look like, you might not be sure which vegetable you’re buying so it helps to know that most American grocery stores do not carry yams.
The lack of yams in stores means that most grocers label sweet potatoes as yams; this is also common with packaged products called “yams.” This article addresses the difference between yam and sweet potato, where the mixup came up, and the uses of the two vegetables.
Are Yams the Same as Sweet Potatoes?
There are a few threads to follow when looking for the mixup between yams and sweet potatoes.
One of the popular theories starts in Louisiana, where farmers began marketing their sweet potatoes as yams to differentiate them from the crops sold from other states.
Origins of Yams (Dioscorea)
There is, however, a rather distinct difference between yams and potatoes of the sweet type. Yams are perennial vines cultivated for their tubers, also known as yams, in temperate Africa, Asia, South America, and the Caribbean.
True yams are an essential part of West African culinary traditions, and the word “yam” itself finds its roots in West African heritage.
In different West African languages, the words “nyami,” “nyam,” and “enyame” all mean “to eat” and are where our term “yam” originates.
Origins of Sweet Potatoes (Ipomoea batatas)
The origins of sweet potatoes begin in South America, Mexico, and the Caribbean. From there, researchers have studied its journey of being traded and carried to other islands and countries where it became a worldwide commodity.
Sweet potatoes are beloved for their nutritious value and high levels of beta-carotene, potassium, and carbs. Note that there are fewer carbs in parsnips vs sweet potatoes if that is a concern.
North Carolina is the number one grower and supplier of sweet potatoes in the USA, followed by California and Louisiana.
Growing Sweet Potatoes
The sweet potato is a plant in the morning glory family and is distantly related to the regular potato.
Most of us are familiar with orange sweet potatoes used as root vegetables, but varieties of sweet potatoes exist that produce purple sweet potatoes as tubers.
Sweet potatoes are sensitive to frost, so wait two to three weeks after the last frost in your area to begin planting. While waiting for the weather to warm, start by buying root sprouts or slips from a nursery or a supplier.
Place your roots in a box of moist sand or chopped leaves and leave them in a warm spot outdoors where the temperature reaches at least 70°F.
Once shoots sprout and reach six to nine inches long, use a knife to cut them off at the root. Dispose of the bottom inch of each root sprout as this piece may harbor disease-carrying organisms.
Create a ten-inch high ridge of soil and plant your sprouts into the ridge three feet apart. Lay black plastic down around your plants to warm the soil and control weeds, or add mulch to the area two weeks after planting. The best vegetable to plant next to sweet potatoes is bush beans. Companion planting benefits both veggies.
Provide your plant with one inch of water each week then stop watering two weeks before harvesting to allow the soil to dry. This time is essential to avoid causing your sweet potatoes to rot by overwatering.
You can tell if sweet potatoes are bad if they are moldy, have an unpleasant smell or are squishy.
Once the difference between yam and sweet potato is clear to you, you may begin to wonder why we continue to confuse the two, especially when yams are so hard to come by in America.
Their scarcity is partly due to their strict growing requirements. While sweet potatoes are sensitive to the cold and frost, yams cannot tolerate any cold temperatures in their growing season, ranging from five to eleven months.
Because of this, yam farming happens in warmer growing zones like eight through ten.
If you’re hoping to grow your yams in New York, regularly hit with brutal winters, you might want to rethink, but it is possible to grow yams in cooler areas with a greenhouse.
To grow sweet potato slips, fill a glass with water and pierce your tuber with several toothpicks. Place it into the glass of water so that half of the yam remains out of the water, supporting the toothpicks’ glass rim.
Place this glass in a sunny windowsill and fill the water as necessary to ensure the water level remains constant. In roughly three weeks, you should see slips growing from the portion of yam not submerged in water.
Once leaves form from the slips, gently twist the sprouts off and lay them into a shallow container of water that allows the top leaves to hang over the edge. Once roots reach an inch in length, you’re ready to plant.
Yams are prolific growers, so the way to plant yams includes spacing your slips with at least one foot between each other and five feet between each row.
For the first week, water your yams daily. Water your yams every other day the following week, and gradually less until you water only once a week.
Avoid fertilizing your different types of yams for at least three weeks, as new slips are sensitive to fertilizer. They benefit from low nitrogen and high phosphorus fertilizer once they begin to grow.
The Visual Difference between Yam and Sweet Potato
Although they are similar, the two tubers have slight visual differences, with yams having brown bark-like skin and pale starchy flesh while sweet potatoes have flesh and skins of various colors.
Garnet is one of the most common types of sweet potato, one of the soft varieties with reddish-brown skin and its signature orange flesh.
The Taste Test for Yams vs Sweet Potatoes
Due to the name mixup, if you get your hands on yams, you might think they’d work as a substitute for sweet potato at your next family dinner, but we’d hold off on making that switch.
Sweet Potato Flavor and Uses
Unlike regular potatoes you boil in preparation for the popular side dish of mashed potatoes, the sweeter flavor of sweet potatoes makes them more suited for desserts.
Common uses for sweet potatoes include baked sweet potatoes, sweet potato casseroles, or sweet potato pie.
To prolong the life of your tubers, freeze yarms and raw sweet potatoes in airtight containers or bags.
Cooking with Yams
Compared to sweet potatoes, yams are drier, earthy, and neutral-flavored. Some say that yams are mildly sweet, but they heavily rely on seasonings to flavor recipes.
Yams are sometimes cooked similarly to regular potatoes by being boiled and seasoned with salt, and some have even taken to using yams to replace potatoes when making fries.
Although candied sweet potatoes don’t have the same ring as candied yams do, we hope you found this article helpful in answering the kitchen table question, “Are yams the same as sweet potatoes?”
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