It's a potato-a sweet potato-or is it? Potatoes, are members of the solanum tuberosum family, while
SweetPotatoes are in the MorningGloryConvolvulaceae family. The SweetPotato probably got linked up as a
potato with the corruption of the word batata, the Indian word for SweetPotato.
To add to the confusion, when is it a yam and when is it a SweetPotato? Yams and SweetPotatoes are terms
used interchangeably in the United States, but yams in America are actually SweetPotatoes that have a
moist texture and an orange flesh. The US Department of Agriculture now requires that the label, "yam,"
always be accompanied by "SweetPotato."
It is thought all this confusion began in1930 when growers introduced a new variety of a very sweet,
orange-fleshed sweet potato, and called it a Louisiana yam to distinguish it from the more common white
SweetPotato. The English word "yam" was adopted from the African word quot;nyamiquot; meaning a starchy,
edible root. Note that SweetPotato is now one word to avoid confusing them with potatoes.
Yams are members of the lily family and originated in West Africa/Asia, while SweetPotatoes are members
of the morning glory family and originated in Tropical America (Peru, Ecuador.) In addition,
SweetPotatoes are the roots of the plant, whereas yams are rhizomes with creeping stems that grow
horizontally at or under the surface of the soil. (Potatoes are tubers.)
There are several other differences. True yams have rough, scaly skins with a long, cylindrical shape
(some have toes) and because they contain more starch then SweetPotatoes, they aren't as sweet. Yams
are larger too, ranging in size from that of a small potato to a humungous 7½ feet long and weighing
SweetPotatoes have thin, smooth skins that depending on the variety vary in color from a pale yellow-to
a deep purple-to a vivid orange. Their short, blocky, shape has tapered ends with flesh colors that vary
from light yellow to pink, red, or orange.
Retailers will often refer to the two types of sweet potatoes as dry (yellow-fleshed) and moist
(orange-fleshed), although those terms do not accurately reflect moisture content. Growers cure both
types of sweet potatoes by storing them in warm, moist rooms for about ten days before they are sent out
to the stores. This helps to preserve them longer, gives them a darker color on the outside, and helps
to convert their starch to sugar which makes them sweeter when cooked as well as giving them a smoother
texture. Generally, only sweet potatoes harvested after October are cured.
North Carolina is the largest producer of sweet potatoes followed by Louisiana and California.
Storage & Selection
Choose uniform sizes that are thick in the middle, taper at both ends, that are firm and free of
blemishes or decay. A decayed spot even if cut away may have already given the whole potato a bad
flavor. SweetPotatoes have thin skins and bruise easily so they should be handled with care. Store
SweetPotatoes between 55°F and 65°F in a dark, dry, cool place, for up to one month, or use within one
week if stored at room temperature. If refrigerated, their natural sugar will turn to starch and ruin
I'd like to see you bake or microwave SweetPotatoes like Russets with their skins left on, because sweet
potatoes are high in nutrition and sweet enough to eliminate the need for gobs of butter. Use somewhat
smaller sweet potatoes that are uniform in size and dress them with a dab of butter (or leave plain) and
add a smidgen of brown sugar or maple syrup.
SweetPotatoes compliment almost all meats and fish, are great in stews, soups, and salads or baked in
breads, pies, custards, and cakes. They naturally go well with other sweet vegetables such as parsnip
and carrots, but they can also handle assertive flavoring such as garlic, sage, rosemary, allspice,
nutmeg, mace, and cinnamon.
Freeze leftover sliced or mashed SweetPotatoes to use later. Keep them from turning dark by adding a little lemon juice.
Tony's Favorite Recipe
Slow-Roasted Mashed Sweet Potatoes
Jewel is a moist variety with a deep orange
flesh, dark, reddish brown skin, and is the one most often mislabeled as a yam. It has a high starch
content that makes it sweet when cooked.
Yellow Jersey is a dry variety that has a
less sweet flavor than the Jewel, and may also be more fibrous.