November is Sweet Potato Awareness Month (SPAM), and I do my part by reminding people that yams are something else entirely. As a foodie and an evolutionary biologist, I feel obliged to be a nudge about this. So here are three images to help.
First, a photograph of a white yam (Ipomoea rotunda) in a bin of sweet potatoes.
Second, a photograph of three cultivars of sweet potato (all Ipomoea batatas) next to a yellow yam (Dioscorea cayennensis).
Third, an illustration of how yams and sweet potato are related (they aren’t). As a bonus, I’ve also indicated the position of potato.
Please share this page with your family prior to Thanksgiving dinner. It will be one less thing to bicker about. If you need more details, here’s my “Yams versus sweet potatoes” page. Read it if you want to know why the slave trade caused the whole “yam” confusion problem.
If you want to sell more orange-fleshed sweet potatoes, craft your labels with “yams” in parentheses, like this:
Sweet potatoes (“yams”)
Because you are a produce manager, you undoubtedly know that a yam is a completely unrelated thing, so using quotation marks will indicate to ignorant shoppers that you are not actually selling yams. As you also surely know, “yam” is regional slang used by some (generally older folks) to refer to a sweet potato that has orange flesh. But if you only have “yams” on label, some shoppers might get flustered and leave for another store that labels sweet potatoes as “sweet potatoes.” Still others are looking for a specific variety of orange-fleshed sweet potato (Beauregard, Jewel, etc.), so list that, too. E.g.,
‘Beauregard’ sweet potatoes (“yams”)
That’s a lot of text, but different varieties are good for different recipes, and some of your customers are over-educated foodies who care deeply about such details. Ideally, cut one in half and cover in plastic wrap to convince skeptical shoppers that it does, indeed, have orange flesh.
I revised the reference card a tad, so here it is again. Please share. If you want to print out a bunch to laminate into wallet-sized favors for your Thanksgiving guests, here’s the PDF. And here are the gruesome details behind this card, if you really want to know.
[#yamgate] For those people fascinated by the confusion some Americans have about sweet potatoes and yams, you should probably watch this clip from The Ellen Show.
During the monologue she showed two photographs: a white-skinned sweet potato (which she called a sweet potato) and an orange-skinned sweet potato (which she said was a yam). That’s basically her joke: for all of you who thought the orange-fleshed tuber was a sweet potato, you have been misled … it’s a yam! Her implication was that the second photograph (orange tuber) was some sort of plant completely unrelated to a sweet potato.
Of course, the monologue is really funny even if you know she’s wrong, and I’m sure she’s was just feigning ignorance (she’s brilliant at that). But when I first heard the monologue, I thought to myself: wow, I wonder whether she’s from Louisiana?? Only somebody from that state would pitch the information in the way she did, I thought. So I Googled her and found her Wikipedia entry … she is.
Louisiana is the state that is actually responsible for the sweet potato / yam confusion. In the 1930s, a sweet potato researcher, Dr Julian Miller, decided that Louisiana could make a lot more money if it started marketing sweet potatoes under the name “yams.” Although nobody really likes to bring it up, “yam” is the word enslaved Africans used for the sweet potatoes, which they were introduced to in the Americas (sweet potatoes resembled the yams they ate in Africa). So Louisiana used that historical fact as a marketing scheme for selling a variety of orange-fleshed sweet potatoes. It really was brilliant, and the guy is a state hero.
Being the swell guy that I am, I’ve offered to send Ellen a yam. It would be hilarious to have a cook on the show deep-fry batches of yams and sweet potatoes and hand them out to the audience. Both are sweet, starchy, and deep-fry nicely. Ellen said at the end of the monologue that when she gets information on sweet potatoes and yams, she’s going to share it, so I think she’s set herself up nicely for this. So far, though, no word from Ellen about whether she would like a yam.
A photo of a yam is below, on right, just in case you’ve never seen one (likely). If you actually want to know more about yams (unlikely), please see my “Yams versus sweet potatoes” page.