Yams are much larger than the sweet potato, thicker-skinned and not nearly as sugary. Instead of the creamy-soft interior of a sweet potato, their cooked texture is more like that of a regular potato. They are typically sold in Latin American or African markets, where yams are an important item in the culinary culture. They are rarely sold in grocery stores.
So how did this confusion begin? The story goes that the lineage lines were crossed many years ago when one farmer growing a specific variety of sweet potato wanted to set it apart from the other growers. As a marketing tool, he called it a yam.
But sweets and yams are as different from each other as apples and oranges. Sweet potatoes, the edible part of the plant's roots, are like ginger root, a member of the morning glory family. True yams are tropical rhizomes related to the lily and amaryllis. (And neither is related to the potato, which is a tuber.)
Sweet potatoes are sweetest during the winter months. When purchasing, look for ones that feel heavy for their size with tight, firm skins. Once home, store in a cool, dark spot, rather than the refrigerator, where they may become moldy quickly.
And sweet potatoes, with or without marshmallows, are what we traditionally eat at Thanksgiving.
Mashed Sweet Potatoes With Pepper and Thyme
2 1/2 pounds sweet potatoes
4 tablespoons unsalted butter, cut into chunks and softened
1/4 cup milk, cream or half-and-half
1 teaspoon chopped fresh thyme leaves
1/2 teaspoon coarsely ground black pepper
1/8 teaspoon ground allspice
1/2 teaspoon kosher salt
Peel sweet potatoes and cut into 11/2-inch chunks. Place in a steamer basket set over boiling water, cover and steam 15 to 20 minutes, or until tender. Drain well and place in a large bowl. Mash coarsely.
Add butter, milk, thyme, pepper, allspice and salt. Mash until smooth and serve warm.
Source: "One Potato Two Potato" by Roy Finamore with Molly Stevens (Houghton Mifflin, 2001).
Roasted Sweet Potatoes and Onions With Rosemary and Parmesan
11/2 pounds red onions (about 3 medium), halved lengthwise, cut crosswise into 1/4-inch-thick slices
1/2 cup freshly grated Parmesan cheese
1 tablespoon chopped fresh rosemary
Set a rack in center and a rack at lowest position in oven and preheat to 375 degrees. Line two large baking sheets with foil. Place sweet potatoes on one sheet; drizzle with 6 tablespoons oil. Sprinkle with garlic, 11/2 teaspoons salt and 1 teaspoon pepper. Toss to coat, then spread in single layer. Place onions on second baking sheet; drizzle with remaining 2 tablespoons oil and sprinkle with remaining 1 teaspoon salt and 1/2 teaspoon pepper. Toss to coat, then spread in single layer.
Place sheet with potatoes on center rack and sheet with onions on lower rack in oven. Roast until potatoes are tender and onions are tender and brown around edges, stirring every 10 minutes, about 30 minutes for potatoes and 35 minutes for onions. (Can be prepared 4 hours ahead. Let stand at room temperature loosely covered with foil. Rewarm uncovered in 375-degree oven about 10 minutes.)
Combine sweet potatoes and onions in shallow bowl. Sprinkle with Parmesan cheese and rosemary and toss to coat. Season with salt and pepper; serve.
Makes 6 servings.
Source: Bon Appetit magazine, November 2002.
Sweet Potato Casserole
3 1/2 pounds sweet potatoes
7 tablespoons unsalted butter, divided
6 tablespoons whipping cream or half-and-half
Scant 1/2 teaspoon ground allspice
Scant 1/2 teaspoon ground ginger
Scant 1/2 teaspoon ground nutmeg
1/2 teaspoon salt
1/2 teaspoon fresh ground black pepper
3 tablespoons brown sugar
3 tablespoons lemon juice
Nonstick cooking spray
2 cups large marshmallows, each cut into quarters
Place a sheet of heavy-duty foil on center oven rack and preheat to 425 degrees. Pierce each sweet potato in several places and place in oven. Bake about 1 hour, or until very tender when tested in the centers. Remove from oven and cool slightly.
When cool enough to handle, open the potatoes and scrape the flesh into a large bowl. Add 6 tablespoons butter, cream, allspice, ginger, nutmeg, salt, pepper, brown sugar and lemon juice. Mash with a potato masher until semismooth. (The dish can be made 24 hours in advance. Cover and refrigerate. Remove from refrigerator 1 hour before baking.)
Spray a 21/2-quart casserole dish with cooking spray. Pile the mashed sweet potatoes into the dish. Bake in a preheated 350-degree oven about 20 minutes. Top with marshmallows and continue baking 25 minutes or until golden on top.
Makes 8 to 10 servings.
Source: "One Potato Two Potato" by Roy Finamore with Molly Stevens (Houghton Mifflin, 2001).
