There is a luscious world of sweetpotatoes (yes, one word. Read on) out there beyond the orange-fleshed variety, and that is the first reason to read this.
Sweetpotatoes stubbornly defy classification with regard to cooking and eating. Skin may be tissue-thin or as thick as cardboard and tinted beige to purple. The flesh may be marigold or mauve and may cook up smooth and creamy or fluffy and granular. Ivory-fleshed when raw, a steamed sweet may turn golden or gray, and may hold a hint of sugar or be truly syrupy.
The taste may suggest pumpkin, chestnuts or vanilla cookies. But if you like sweetpotatoes, sampling your way through the particulars will be an agreeable assignment.
The second reason to keep reading is to implore you to believe that none of them is related to yams or potatoes.
With Latin, it’s easy to explain: Ipomoea batatas originated in the New World, then traveled to the Old. So did Solanum tuberosum, but later. Dioscorea, a genus with Old World and New World members, has no connection to either.
When translated from these Latin names into common names, confusion arises. First, there is the mixup between sweet potato and potato: Columbus introduced the sweetpotato (I. batatas) to Europe with a Native American (Taino) name, written variously as “batatas,” “patate” and “potat.”
So “potato” meant sweetpotato in Europe until nearly a half-century later, when what we now call the potato (S. tuberosum), landed there and was also called “potato.” By distinction, I. batatas became the “sweet potato.” Now you can understand why classifiers have begun using a single word, sweetpotato: It was an attempt to prevent grouping and mixing with potatoes.
Then there is the confusion between sweetpotato and yam. This has two parts–one historical, one recent. True yams are species of Dioscorea, starchy tuberous roots that are rarely sweet. The English word “yam,” surmised to be of West
African origin, came via a word recorded by Portuguese slave traders, inhame (pronounced een-yam). This word also was used in the American South, but erroneously applied to the sweetpotato.
In the 1930s, promoters of Southern-grown sweets hit on the word “yam” for a campaign to set apart their Louisiana product from drier, paler sweets grown in New Jersey, Maryland and Virginia.
In sum, sweetpotatoes, potatoes and yams are not related, despite the shared common names. If Latin is used, the mixup cannot occur.
Outside the United States and Europe where sweetpotato consumption is minimal, I. batatas is not just a minor addition to a fall festival. It is one of a mere handful of food crops considered “major,” that is, one that measures above 100 million metric tons per year. Well above 90 percent of sweetpotatoes are grown in Asia, and these are rarely orange.
“The moist, orange-fleshed sweetpotato we grow is an exception favored only here and in Australia,” says Stanley J. Kays, a horticultural scientist at the University of Georgia in Athens. “Orange color is linked to pumpkinlike flavor, which Americans like, but others don’t.”
He cites the example of a Chinese grower who, pressed to explain why he didn’t plant more American sweetpotatoes, answered: “If we wanted something that tasted like pumpkins, we would have grown pumpkins.”
The differences
Having claimed that sweets cannot be grouped, I am now going to group some, because there is no way to take them on one at a time.
– Orange-fleshed sweetpotatoes, such as Beauregard, the primary commercial type, and the smaller-volume Jewel and Garnet, are “traditionals” in North American markets. When cooked, they have a soft, sometimes squishy feel in the mouth and a pumpkin flavor. They are always decidedly sweet.
That sweetness “varies with the cultivar, how they are handled after harvest, and the length of time after harvest,” Kays says. “Sweetness can be quite variable and a major frustration for consumers.”
– The sweetpotatoes preferred outside the U.S. and Canada are white-fleshed and not usually as sweet or soft as a Beauregard–but they too are highly variable. It is reasonable to generalize about these burly boniato types, which are broadly represented in Latin and Asian markets throughout the United States. Aromatic (freshly cut, they suggest violets) and less sweet than our orange varieties, they are fluffier and drier, like a blend of traditional sweetpotato, chestnut and a baking potato. They may be rugged and rosy-skinned, or pale and round.
– Asian or Japanese or Korean sweetpotatoes are market catchall terms for various rose-skinned, ivory-fleshed cultivars developed in the Far East. They fall between the drier boniato types and the moist-fleshed whites (discussed below). Baked, the flesh turns fresh yellow, while the texture is smooth and medium dry (like marrons glaces, or candied chestnuts). The flavor is warm, medium sweet, closer to traditionals. Steamed, the skin slips off neatly, leaving a satiny, creamy cylinder rather like a ripe banana in color and texture, and very sweet. It slices sleekly although it feels like puree in the mouth.
– Pale, moist, soft sweets are generally close to traditionals in texture and sugar but have beige skin and white-to-yellow flesh. They appear erratically at local markets in California, New Jersey, North Carolina and Virginia. The Hayman sweetpotato has recently been revived in the Chesapeake Bay area. It is small, unassuming, scruffy and stodgy. Extremely moist–syrupy juice drips from it–the Hayman should please those who like their marshmallows built in. Bake it only: Other methods produce a heavy, pasty texture.
Basic use
For me, there is really just one question: Is the sweetpotato at hand better baked or steamed? A trial is the only way to know. Either way, a sweetpotato makes a rewarding, nutritious snack, breakfast, lunchbox item or little meal. (I love it with a glass of buttermilk.) More than plain cooking is gilding the lily. However, others like their sweets embellished.
The Asian types and pale, moist, soft sweets can be used in recipes for traditional sweets. For boniato types, you’ll need to take into consideration their comparative dryness, pale color, rather delicate flavor, and usually lower sugar content. Bake, fry, boil, roast, steam, saute, mash, puree, cream and combine in custards, flans, puddings, pies or muffins. When frying, do not exceed 325 degrees or cut them too thin or they’ll burn. When boiling, keep them completely immersed in water or the flesh will get spotty.
Selection
You can’t tell a sweetpotato by its cover. Some of the most rich and perfumed wear the dullest coats. If they are solid and dry, try them one and all, pale and gaudy, to find your favorites.
Sweetpotato season begins, not at harvest, but after a curing period of four to eight days to heal splits and firm up skin, and then weeks of storage, “during which the enzymes required for the formation of sugar from starch during cooking are greatly increased,” Kays says. Generally speaking the season starts around mid-November, but (commercially) stored sweets will last into the spring. Heft a few to choose those that are heaviest for their size. Do not buy them from a chilled bin: Refrigeration destroys these tropical tuberous roots.
Boniato, which grows only in the tropical tip of Florida and farther south, is picked virtually year-round and is not cured and stored. The thin skin is easily bruised, so the boniato spoils rapidly. Choose rock-hard boniato, checking each root for soft or moldy spots. When grown in pebbly soil, as they are in Florida, they develop gnarled forms and blotched skin, but the flavor is not affected.
Storage
Do not stock up on sweets. Buy only what you plan to cook. Store in a basket in a ventilated area, preferably at cool room temperature, for as short a time as possible. Do not refrigerate. Do not enclose in plastic. If sprouts appear, rub them off.
Preparation
Scrub well with a brush if you’ll be baking them with the skin. For boiling or steaming, simply rinse, then peel after cooking. When you peel before cooking, keep them in water to prevent discoloration.
Most sweetpotato types can be cooked in the following ways. Whichever way you choose, test carefully by piercing with a knife tip to be sure it is completely cooked creamy soft in the very center. Timing given below is for sweets of about 1/2 pound.
Steaming: Quarter scrubbed potatoes, set on a rack; cover and steam over boiling water until very tender, about 20 minutes. Peel and slice to serve warm, drizzled with butter, lime juice and a touch of hot pepper sauce. Or serve at room temperature with gingered yogurt.
Baking: Bake sweetpotatoes in their scrubbed skins (no foil, no butter) for deep, concentrated flavor and color, and a firmer, starchier texture. Set scrubbed whole or half sweets in a shallow pan in a 350- to 400-degree oven; bake until very tender in the center, 40 to 50 minutes.
All baked sweetpotatoes are delicious, but fine boniatos are extra special: The skin bakes crusty-hard and tastes delicious pulled off in chunks and buttered. Because the skin becomes so crunchy, you must test carefully for doneness to be sure the center is creamy-soft.
Boiling: Boil peeled chunks of boniato and other dryish pale sweets in salted water for gently sweet flavor and texture. (Orange- and yellow-fleshed types lose flavor when boiled, unless they are boiled in only a small amount of seasoned liquid to add flavor.) Cook until tender throughout, about 25 minutes. Keep submerged, or the flesh becomes spotty and gray.
Microwave? Never! All sweetpotatoes are compromised if not destroyed by the microwave oven.
Baked sweetpotato-apple puree with horseradish
Preparation time: 40 minutes
Cooking time: 1 hour, 40 minutes
Yield: 6 servings
This is a useful, simple-to-make puree that reheats wells, thanks to the addition of apple. To complement the fruit’s juiciness, use boniato or other relatively dry-fleshed sweet potato. The hot-sweet bite of fresh horseradish is particularly intriguing, but the puree adapts to other accents such as grated fresh ginger, chipotle chilis packed in adobo sauce, lime juice or balsamic vinegar. For a pretty presentation, pipe the puree through a wide star tube. From Elizabeth Schneider’s “Vegetables from Amaranth to Zucchini.”
9 whole cloves
5 medium sweetpotatoes
4 tart apples, such as Granny Smith
2 tablespoons unsalted butter, melted
2 teaspoons freshly grated horseradish plus more to taste
Salt, white pepper
1. Heat oven to 400 degrees. Insert 1 clove into each sweet potato and each apple. Place in foil-lined roasting pan. Bake until apples are soft, about 1 hour. Set aside to cool. Continue baking sweetpotatoes until very soft, about 25 minutes longer. Set aside to cool slightly. Discard cloves.
2. Increase oven temperature to 425 degrees. Remove apple peels and stems; discard. Remove sweet potato skins; discard. Press apples and sweet potatoes through medium disc of food mill or large holes of a grater into medium bowl. Stir in butter, horseradish and salt and pepper to taste. Transfer mixture into lightly greased 8-inch square baking dish. Bake in upper level of oven until slightly browned and bubbling at edges, about 15 minutes.
Nutrition information per serving:
225 calories, 15% calories from fat, 4 g fat, 2.4 g saturated fat, 10 mg cholesterol, 20 mg sodium, 46 g carbohydrate, 2.8 g protein, 6 g fiber
Roasted sweets, fennel and onions
Preparation time: 20 minutes
Cooking time: 1 hour
Yield: 10 servings
Roasting caramelizes the sugary juices in vegetables, bringing sweetness to the surface. Once the dish is cooked, do not cover or the vegetables will get mushy. Serve with pork, chicken or game. From “Vegetables from Amaranth to Zucchini.”
3 medium sweetpotatoes
2 fennel bulbs with green fronds
2 large white or red onions
1/3 cup sherry vinegar or red wine vinegar
1/4 cup olive oil
1 1/2 teaspoons kosher salt
1 teaspoon hot pepper sauce
1. Heat oven to 425 degrees. Peel, rinse and chop sweetpotatoes into 1-inch cubes; drop into cold water in large saucepan. Heat to a full boil; boil 3 minutes. Transfer with slotted spoon to a lightly oiled large baking dish or roasting pan, reserving boiling water in the pan.
2. Trim fennel fronds; set aside. Quarter bulbs. Drop fennel into water; return to a boil. Cook 3 minutes; drain, core and chop. Peel and chop onions. Add fennel and onions to baking dish. Blend vinegar, oil, salt and hot pepper sauce in small bowl. Cover vegetables with vinegar mixture.
3. Roast sweetpotato mixture, turning often to coat with vinegar mixture and pan juices. Cook until browned and fully tender, 40-60 minutes. Chop reserved fennel fronds, sprinkle on top for garnish.
Nutrition information per serving: 115 calories, 41% calories from fat, 6 g fat, 0.8 g saturated fat, 0 mg cholesterol, 320 mg sodium, 16 g carbohydrate, 1.7 g protein, 3 g fiber
Diced rum-raisin sweetpotato bake
Preparation time: 20 minutes
Cooking time: 1 1/2 hours
Yield: 8 servings
Peeled, cubed and baked with juice, rum, sweet spices and raisins or cranberries, sweetpotatoes deserve more than a one-time Thanksgiving appearance. Any type of sweet will work here, but one that turns yellow with baking will have a particularly warm look. From “Vegetables from Amaranth to Zucchini.”
1 1/4 cups cranberry juice or apple cider
1/3 cup dark rum
2 tablespoons brown sugar
1 tablespoon hazelnut or walnut oil or butter
1 teaspoon kosher salt
1/2 teaspoon allspice
1 teaspoon ground coriander
1/4 teaspoon grated nutmeg
3 pounds sweetpotatoes
1/3 cup dried cranberries or raisins
1. Heat oven to 375 degrees. Combine juice, rum, sugar, oil, salt, allspice, coriander and nutmeg in a small pan. Heat, stirring, until sugar dissolves. Remove from heat.
2. Peel sweets and cut into 3/4- to 1-inch cubes. Spread sweetpotatoes and cranberries in lightly oiled 2- or 3-quart casserole. Pour juice mixture over sweet potato mixture.
3. Cover tightly, bake until tender, 1 hour. Uncover casserole; raise heat to 425 degrees. Bake, basting several times, until juices are thick and bubbling and top has browned, about 1/2 hour.
Nutrition information per serving:
180 calories, 10% calories from fat, 2 g fat, 0.2 g saturated fat, 0 mg cholesterol, 250 mg sodium, 40 g carbohydrate, 2 g protein, 3.8 g fiber
