Sweet potatoes are emphatically not the same vegetable as yams, which can grow to be 5 feet long. This may come as a surprise, but sweet potatoes are not related to potatoes, either. They are actually members of the morning glory family, whereas potatoes belong to the nightshade family. But they’re nearly as versatile in the kitchen as regular potatoes and can be cooked in many of the same preparations, though the techniques need to be adjusted to account for the higher sugar and lower starch content of sweet potatoes. Don’t do this: Refrigeration will cause sweet potatoes’ cores to change texture and become distressingly similar to a damp cork. Do this: Store them in a cool ventilated spot for up to 1 month. Or at room temperature, they will keep for a week or two.