I've got a Thanksgiving related question. Every year my Aunt Gayle brings her famous candied yams, which I'm really looking forward to. I was always under the impression that yams and sweet potatoes are the same thing, but someone told me recently that they aren't. Now I'm a little confused and I'm not exactly clear on what the difference between them is. Any help with be greatly appreciated.
That is a very good question and is indeed confusing. First of all, yams and sweet potatoes aren't even members of the same family and hail from completely different parts of the world. Although they are both tubers, sweet potatoes come from South America and are a member of the morning glory family while Yams are a member of the lily family and originated in Africa. Its name is derived from the African words njam, nyami, or djambi, which means "to eat."
The most common variety of sweet potatoes are Garnet, Jewel and Beauregard and they tend to get classified by the color of their flesh - either white, yellow, orange, or purple. This is where it gets confusing. The variety with the orange flesh are often sold in supermarkets as "yams" even though they aren't. The two vegetables' shapes can be similar, long with tapered pointy ends, but the skin of a yam is usually dark brown, almost black, and has a rough texture. They are starchy and when cut, release a substance that make them feel slippery, like certain squash do. When they are cooked, the texture is very moist and slightly stringy. Cooked orange-fleshed sweet potatoes have a similar texture to that of a yam, however the white-fleshed variety are not as sweet and have more of a grainy texture, like a regular potato.
When choosing yams and sweet potatoes, select ones that feel firm and have unwrinkled flesh. Store them in a cool, dark, dry place - not the refrigerator. When cooking, it's recommended not to boil them, as they can lose much of their flavor. Instead, wrap in aluminum foil and bake in the oven until tender, which should take an hour or so. Or peel and dice or slice them, douse with melted butter or olive oil, dust with spices and roast them in the oven until they've gotten slightly caramelized. Obviously sweet pototes work nicely with brown sugar and maple syrup, although because of their sweet flavor, they also tend to pair well with ingredients that are salty, spicy or have some acidity, such as bacon, cayenne pepper or lime juice.