Difference Between Yams and Sweet Potatoes

Yams and sweet potatoes are vegetables, which are often mistaken for each other. It has been observed in some regions, like the United States, that sweet potatoes are marketed with the label of yams. In fact, as per the U.S, Department of Agriculture rules, packs with sweet potatoes must have an additional label with the term 'yam' printed on it. All these factors add up to the confusion in general public about sweet potatoes and yams. It has become a common misconception that both these vegetables are same and the names are used interchangeably.

Yams Vs Sweet Potatoes

Even though the terms sweet potatoes and yams are used interchangeably, both are entirely different vegetables. The confusion between the two maybe due to the slightly similar looks of some varieties. The marketing of these vegetables using both terms adds up to the confusion and now most people believe that both vegetables are the same. The truth is that yams and sweet potatoes are entirely different vegetables.

Botanical Difference: Yams and sweet potatoes belong to two entirely different plant families. While yams belong to genus Dioscorea of Dioscoreaceae family, sweet potatoes ( Ipomoea batatas) are classified as a member of the genus Ipomoea and family Convolvulaceae. While yams can be related to lilies and grasses, sweet potatoes can be distantly related to potatoes. Sweet potatoes are also referred to as 'tuberous morning glory', as the family include garden flowers called morning glories.

Difference in Shape and Size: You can also distinguish between yams and sweet potatoes by checking the shape and size of the vegetable. While sweet potatoes have thin and smooth skin, yams possess thick and rough skin, which can be scaly too. The skin of yams resembles the bark of trees. As far as the shape is concerned, sweet potatoes have somewhat tapered ends and are comparatively short and stubby. Most of the yams are cylindrical and long, but some varieties have a round shape, like a big bowl. Yams can grow so big and long that sometimes it reaches a length of around seven feet and more.

Difference in Color: The difference between yams and sweet potatoes can be made out from the color of the vegetable. The skin color of yams ranges between brown to black, whereas in case of sweet potatoes, it can be pale yellow, orangish yellow, red or purple. While the flesh of yams can be off-white, pale yellow, purple or red in color, sweet potato flesh color is pale yellow in almost all varieties except the orange one, which has a bright orange flesh. The flesh color of both vegetables may vary with the variety.

Difference in Taste and Texture: Yams and sweet potatoes can be differentiated through their taste and texture. While sweet potatoes are sweet in taste (orange skinned ones being sweeter than the pale yellow one), yams are more starchy than sweet. You can feel the difference between yams and sweet potatoes while eating these vegetables. While sweet potatoes feel more moist (pale yellow one is slightly crumbly too) in texture, yams have a dry texture.

It is said that initially only the soft and dark-skinned variety of sweet potatoes were cultivated in the United States and the African slaves used to call these vegetables, yams, as they resembled the real yams of Africa. So, when the hard varieties with pale skin were introduced, there was a confusion. This led to the former sweet and dark-skinned ones to be termed as yams and the latter entrant as sweet potatoes. However, the confusion still continues. But now you can easily distinguish between them with the help of the information given above.