FoodFood InformationVegetablesRoot Vegetables
The sweet potato is a member of the morning glory family. It originatedin Central America but is now grown in all areas of the world that havesubtropical climates. It is a near-perfect food and is a staple in manyof the world's under developed nations.
We mistakenly call one type of sweet potato a yam. The yam is of a differentbotanical genus, but is often used as a substitute for the sweet potato.
There are two types of sweet potatoes. The ones that we often mistakenlycall yams have a deep orange-colored flesh and are very moist andsweet when cooked. They are grown in most of the southern states, with NorthCarolina, California, and Louisiana as the top producers. Thanks to a curingprocess, these sweet potatoes are available twelve months of the year.
The other type of sweet potato, which is known as the white sweet orJersey sweet, is pale yellow or off-white in flesh color. These arenot nearly as moist and sweet as the orange-fleshed variety and, exceptfor limited pockets of regional preference (Philadelphia and South Jersey),have been almost completely displaced. Yet in Grandma's day the white sweetshad about 90 percent of the market.
While sweet potatoes are available year-round, the two lightest months areJune and July. During those months they are nearly a year old and the qualityslips as the price rises. The most flavorful sweet potatoes arrive in marketduring August, September, and October. These are uncured and shipped tomarket directly from the field.
Freshly harvested sweet potatoes have a very short shelf life. Because theyhave a very high moisture content, they are prone to spot and decay. Atbest they last four to six weeks before they start to break down. By placingthem in a kiln and removing much of this moisture, their shelf life canbe extended from a few weeks to more than eight months. Kiln dried sweetpotatoes are called cured; those that are not kiln dried are called uncured.
The cured sweet potato isn't quite as soft and moist as the uncured sweetpotato; so those that are purchased from August through October will havethe best flavor. All the sweet potatoes that are in market during that threemonth period are uncured; those sold from November until the following August,when the new crop arrives, are cured. There is only one crop per year.
Sweet potatoes are a subtropical vegetable that thrive in warm weather andcan't tolerate the cold. Never store them in the refrigerator or they willcut black after cooking. Sweet potatoes are almost as sensitive to refrigerationas bananas are.
When selecting sweet potatoes, always choose those that are firm and shapelyand have clear, unmarked skins. Those of medium size are your best bet ifyou are going to bake them whole, but they usually sell at premium prices.Very small ones taste fine, but may be more trouble to prepare than theyare worth. Jumbo ones are good for boiling but take a long time to bake.However, the jumbos usually sell for about half the price of medium sweetpotatoes, at least at the wholesale level.
WHEN TO BUY: Available year-round but at peak in August, September and October
WHAT TO LOOK FOR: Firm, shapely vegetables of medium size with clear, unmarkedskins
HOW TO STORE: Do not refrigerate
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