Okay, so I set out to set the record straight about the difference between a sweet potato and a yam, but the more I read, the more sources I consulted, the more confused I became.
One is orange. The other is white. Wait. Both are orange. No, no, no. The flesh of a sweet potato is yellow. And if you don’t like those colors, there’s also purple, pink and dark brown! Aaaarrgh!
Let me break it down for you.
According to The Joy of Cooking, when they say sweet potatoes, they are referring to the yellow-gray to brown skin kind, the ones with the yellowish-white, dry, mealy flesh. When they say yam, they mean those with the copper skin and sweet, orange flesh. Okay, good. That’s what I thought. But wait! They go on to say that true yams are not related to any of these sweet potatoes. “They are tropical tubers with crisp, bland, white to yellow flesh.” Huh? So why call it a yam, if it’s really a sweet potato? That’s ridiculous and erroneous, if you ask me.
Looking at The Essential Cookbook, which is loaded with information and pictures on almost every type of food and cooking equipment you can think of, confirmed that those orange things that we call yams, are indeed sweet potatoes. Their pictures show an orange-fleshed sweet potato, and a yellow-fleshed variety, though the look the same to me. According to them, the yam, on the other hand, is white or yellow, similar in texture to potatoes, and is much sweeter and moister than the sweet potato.
Yeah, that didn’t help, did it? What about that yellow-white, mealy, dry sweet potato The Joy of Cooking mentioned? And why do they say true yams are bland, when The Essential Cookbook claims they are moist and sweet?
Let’s turn to source number three: the Sunday’s at Moosewood Restaurant Cookbook. They say that, in the United States, all those orange tubers, large or small, short or long, tan-colored or brick-red, are all sweet potatoes. True yams are white fleshed and grow only in tropical countries. Well, that’s nice, but bananas grow only in tropical countries, and we can get them!!
They also say there are two varieties of the sweet potato: the dry flesh and the moist flesh. The potatoes with the brick red exterior are moist flesh, and are the type most often mislabeled yams.
This still didn’t entirely clarify the issue for me. While I can now positively assert that those orange-fleshed things are sweet potatoes, I’m still confused about the yam. Since The Joy of Cooking is the only source that, so far, mentions a yellowish-white variety of a sweet potato, I have to wonder if they are wrong. Is this actually a yam? And if the yam is only grown in tropical climates, and not often found in markets in the United States, then what were those thick tannish-yellow skinned things with the sweet white flesh I bought from Safeway last year but haven’t been able to find since? Was that a yam? Did I actually taste a true yam? The elusive, true, yam?
To try and answer that question, I did some digging online. On the Seeds of Knowledge website, I found an article by Jennifer A. Wickes the editor at “Cookbook Reviews” and “Cooking With The Seasons.” She said there are two varieties of the sweet potato, and one is, indeed, a pale version.
The botany site at UCLA sounded eerily like The Joy of Cooking, saying “sweet potato has many cultivated forms, but in the United States two forms are common: (1) the dry, mealy, yellow sweet potato, and (2) the watery, orange ‘yam,’ which is not, of course, a true yam.” But okay, I was getting somewhere. There is a white-fleshed variety in addition the more common orange-fleshed kind. And both are sweet potatoes. Well, unless they are yams…
I was still not sure if what I purchased last year was a true yam. But looking at the pictures at The Cook’s Thesaurus has me thinking not. Sweet potato number four is the culprit. And it is, indeed, a sweet potato. (The kind I like better, in fact!) So unless you’re in the tropics, or a specialty market, you’ll most certainly be purchasing sweet potatoes. No matter what they are labeled.
