By Carie Birkmeier EBS STAFF

Despite what you might think, the yams that you find in your supermarket are likely orange sweet potatoes masquerading as yams. Years ago, farmers started calling their sweet potatoes yams to differentiate their crop from other potatoes in the market. This confusing trend stuck, and grocers today continue to label orange sweet potatoes as yams to distinguish them from other varieties and colors of sweet potatoes.

True yams are a completely different vegetable entirely, and it’s likely you’ve never even seen one. They have thick, textured, almost bark-like skin and white flesh, and an appearance closer to that of a yucca root. Its texture is more like that of a russet potato than a true sweet potato, but with more nutrients and complex carbohydrates.

Yams are most traditionally used in West African—their native region—and Caribbean cooking. They are difficult to find in traditional grocery stores and markets, and are more easily found in specialty food stores.

It’s helpful to know that there are several varieties of sweet potatoes, and grocery stores use the terms sweet potato and yam quite interchangeably. To make it even more confusing, this can vary from store to store. From what I’ve observed, orange sweet potatoes will be labeled as yams and white-fleshed sweet potatoes will keep their actual name. So, if you’re looking for a white-fleshed sweet potato, buy a sweet potato. If you want orange flesh, buy a “yam.”

Since you probably won’t find a true yam at your local grocer, here is a breakdown of the varieties of sweet potatoes most commonly available in the U.S.:

Orange sweet potatoes are likely what you think of when picturing a sweet potato or yam. They have brown skin and deep orange flesh. This variety is commonly used to make sweet potato fries, and the sweet potato pie on your Thanksgiving table. Their nutrient rich flesh makes a great meat substitute for vegetarians. Because they have more water content than other varieties, they are a good option for mashed and pureed preparations.

White sweet potatoes have an appearance similar to russet potatoes, but contain many of the same nutrients as orange sweet potatoes, albeit less beta carotene. Their flesh is drier so they work well in applications where you want to control the moisture in the dish, such as when making gnocchi. Their hardy texture stands up well when roasting, so you won’t be left with a mushy result.

Purple sweet potatoes, like blueberries, contain anthocyanins, which provide their color and high levels of antioxidants. Be aware that their rich color acts like a dye and will turn all other ingredients purple if you don’t cook them separately. This variety adds a punch to presentation, but has the same earthy taste as other varieties of sweet potatoes.