Published November 1, 2002. From Cook's Illustrated.
Does a sweet potato by any other name still taste as sweet?
I grew up thinking that sweet potatoes came in a can. I am not alone in my sweet potato ignorance. Though most people would point to the produce aisle when asked where to find a sweet potato, many of those people would not know the difference between a sweet potato and a yam. In this country, the two terms have become interchangable, both referring to the orange-skinned, orange-fleshed, and sweet tasting root vegetable traditionally found next to the potatoes.
But there is a world of sweet potatoes that extends far beyond these orange confines. Ninety percent of the world's sweet potatoes are grown in Asia, where they are most often white-fleshed and neither as sweet nor as soft as the traditional orange-fleshed varieties we know in the United States. Neither the orange nor the white sweet potatoes have any relation to a true yam, which is covered with a thick, fibrous skin and is starchy and fairly bland tasting.
We wondered just how deep the differences in sweet potatoes ran, so we gathered seven varieties and sampled them in our Mashed Sweet Potatoes. We tried three traditional varieties (traditional at least to those of us raised in the United States and Europe)-Beauregard, Jewel, and Red Garnet-and four non-traditional-Japanese White, White Sweet, Batata, and Okinawa.
In the traditional category, the Beauregard (usually sold as a conventional sweet potato) was favored for its "standard sweet potato" flavor and "basic, all-around good" quality. The Jewel placed second with its "robust sweet potato flavor," though some found the flavor "weird and sour." The Red Garnet was the most savory of the bunch, with a texture deemed "very loose."
Of the non-traditional varieties, the Japanese White was the hands-down winner, praised for its "heavy chestnut flavor" and "velvety" texture. Runner-up White Sweet was dubbed by one taster as "not quite as good as Japanese White but very good." Coming in at the bottom of the ranking were the Batata and Okinawa, both ultimately losing points for color and lackluster flavor-the Batata with its "ugly gray" hue and the Okinawa with its "freaky" purple haze.
Traditional Varieties (in order of preference):
BEAUREGARD: "Buttery," "sweet, honest," "nice color."
JEWEL: "Beautiful color," "only slightly sweet."
RED GARNET: "Not very sweet," "squash-like," "watery."
Non-Traditional Varieties (in order of preference):
JAPANESE WHITE: "Unbelievable," "awesome," "rich and sweet."
WHITE SWEET: "Lightly sweet and rich," "one-dimensional."
BATATA: "Ugly," "round and rich," "not bad."
OKINAWA: "Amazing color," "nutty," "bland but beautiful."