The Sweet Potato vs. Yam Debate on “Weekend America” (which one do you use?)

Print Print | Print Email this to a friend | November 21, 2008
Filed Under Uncategorized

A couple of days ago I got an email from Ochen Kaylan, a producer of American Public Media’s Weekend America. He was gathering information about the differences between Sweet Potatoes and Yams, for a Thanksgiving show, and invited me to participate. We all know the sweet, sticky, gooey side dish that is loaded up with brown sugar, spices, lots of butter and the ubiquitous marshmallow topping. But people always wonder which to use, sweet potato or yam? Really what is the difference?

It turns out that sweet potatoes and yams that we find here in the States are really all sweet potatoes. What we think of as yams are called this by mistake. It started long ago when the slaves were brought over and identified sweet potatoes with the “nyami” from Africa. The name stuck and we’ve been eating a misnomer ever since. To further the complication, neither of them are really potatoes at all! They are both tubers, although not even related to each other. In fact, the sweet potato is a cousin of the morning glory flower. There are about 200 varieties of true yams, of which none grow in the States. They are all different colors and sizes, the largest measuring almost 7 feet!!! I was so hoping to find one of those.

Still confused at which one to use for Thanksgiving, we set off to find out what the differences are and how they will effect your recipes. I’ve baked, boiled, sauteed, mashed and grated them both, but until now I didn’t really know what I was dealing with. Our journey started at an Asian Market called Shuang Hur on Nicollet Avenue in Minneapolis. They had bins filled with things that looked like sweet potatoes or yams, sort of. They weren’t orange or tan like I am used to seeing, but the shape suggested a relationship. They were black, white, red and some had rough, even “hairy” skins. The bins weren’t market so one of the employees acted as our guide through this exotic produce isle. It turned out they were authentic yams, not sweet potatoes at all. We bought a bunch and I headed home to bake them along with some sweet potatoes and “yams” I’d bought at Whole Foods and my local coop.

This is what we found:

From top: Camote (sweet potato), Purple “ube” Asian Yam, Sweet Asian Yam, Yampi Yampi, Jewel “yam” (sweet potato), Sweet Potato, Garnet “yam” (sweet potato). In order to taste all of the varieties on an equal playing field we baked them. I like baking sweet potatoes and yams over boiling because it caramelizes the natural sugars and makes them more intense. These sweet tubers are not only tasty and beautiful but they are also packed with vitamins A & C.

Here is the flesh of the sweet potatoes. Both Ochen and I thought that the Jewel “yam” was the sweetest, then the Garnet “yam”, the Camote and finally the sweet potato was the least sweet of the bunch.

These are the authentic yams that we found at the Asian market. The purple “ube” yam was the sweetest of all the yams, sweet potatoes and fake “yams!” Its color was disarming and like no other natural food I’ve ever seen. It was delicious and I will definitely be buying more. The color alone had me, although I was disappointed in how it baked in the pots de creme (below). The Yampi Yampi was dry and mealy and not at all sweet. The sweet “yam” was creamy and sweet, but not compared to the purple yam. This one I have in “” because I couldn’t find any information on it and wonder if it isn’t a sweet potato?? If you know please tell me!

Our next experiment was to bake the different “yams,” sweet potatoes and real yams in a recipe. I was curious if the differences we detected in the plain baked version would hold true in a dish with other flavors competing with it.

First I made a Pots de Creme:

1 1/2 cups mashed sweet potato, purple yam or jewel “yam”

6 large egg yolks

1/4 cup honey

4 cups heavy cream

6 whole cloves

1/2 piece of peeled ginger

1 cinnamon stick

1 vanilla bean

1/3 cup brown sugar

Preheat oven to 325°

In a heavy bottomed pan gently heat the cream with the ginger, cloves, cinnamon, vanilla and brown sugar. Allow to gently simmer and then turn off heat. The longer you allow the cream and spices to steep the more intense their flavor will be. This can even be done the day before. When ready to prepare the custard strain the spices from the cream.

Add the yolks, honey and mashed sweet potato to the cream. With an Immersion Blender or whisk blend everything together very well. I like to use the immersion blender because it further breaks up the potato. If you are not using one, you might want to strain the custard before putting in the cups and baking.

Bake as I did for the Chai pots de creme recipe.

Neither Ochen nor I could detect any difference between the pots de creme using the different varieties of yams and sweet potatoes. The color of the purple yam mixed with the egg yolks turned the whole thing a tinge gray and it had the slightest graininess to the texture, so I’d not use it for this again.

For the second recipe I decided to use grated sweet potatoes and yams to see if the flavor would be enhanced. Otherwise the list of ingredients are quite similar.

The result was surprising. Unlike the pot de creme we really could taste a difference between the different varieties and it wasn’t all that subtle. I guess leaving it raw and coarsely grated made the difference.

This is an old recipe for sweet potato pudding that is meant to be served with whipped cream spiked with Jack Daniel’s whiskey. It is important that all the ingredients are at room temperature.

Tennessee Old Maid’s Sweet Potato Pudding from Classic Home Desserts:

1/4 cup (1/2 stick) unsalted butter

1/2 cup packed brown sugar

1/4 cup sugar

2 large eggs, beaten

1 teaspoon ground cinnamon

1/4 teaspoon fresh grated nutmeg

1/4 teaspoon ground clove

pinch salt

2 1/2 cups coarsely grated raw peeled sweet potato, purple yam or jewel “yam,” well packed

1 1/2 cup warm half&half or whole milk

Preheat the oven to 350°

Cream together the butter and sugars until well blended and very light. Beat in the eggs; beat in the spices and salt. Stir in the sweet potato or yams; add the milk and mix thoroughly. At this point the mixture may appear to separate, but proceed because it doesn’t seem to effect the finished pudding.

Bake until set, about 25-30 minutes. Cool to room temperature and serve with whipped cream that you spike with Jack Daniel’s. I tended to like this pudding made with the sweet potato and Ochen liked with best with the super intense purple yam. You try and decide with you like best!

Here are more recipes to make with sweet potatoes or “yams” or real yams!

Vegetarian Cooking for Everyone by Deborah Madison has a Sweet Potato Souffle

Suvir Saran’s American Masala: 125 New Classics from My Home Kitchen
has a recipe for spicy Sweet Potato Chaat that will make you weep.

Lynne Rosetto Kasper and Sally Swift have a recipe for “Yams” with Ginger and Scallions in their book The Splendid Table’s How to Eat Supper: Recipes, Stories, and Opinions from Public Radio’s Award-Winning Food Show

A Southern baking bible Biscuits, Spoonbread, and Sweet Potato Pie by Bill Neal has amazing recipes for Sweet Potato Pie and Biscuits.

Irene Sax wrote an article recently for Saveur magazine with a classic Sweet Potato Casserole.

Finally the quintessential candied “yam” recipe from Mark Bittman’s How to Cook Everything, albeit a healthier version.

Jeff and I have also been working on some recipes for our follow up book to Artisan Bread in Five Minutes a Day that include sweet potatoes, maybe now I will throw in a yam recipe as well?

Due to the fact that I now have about 10 pounds of baked sweet potatoes and yams my family is eating them with everything. I just made a Sweet Potato Milk Shake that I just have to share with you.

1 cup baked sweet potato of your choice (I used jewel “yam”)

3/4 cup whole milk

3 cups extra rich high premium vanilla ice cream of your choice

2 tablespoons maple syrup

1/2 teaspoon ground cinnamon

1/8 teaspoon ground ginger

1/8 teaspoon fresh ground nutmeg

1/8 teaspoon ground allspice

2 tablespoons bourbon (optional)

Mix well in a blender and split between 2-4 cups. Seriously fabulous, like a cold creamy sweet potato pie!

Happy Thanksgiving!

Print Print | Print Email this to a friend

Comments

59 Responses to “The Sweet Potato vs. Yam Debate on “Weekend America” (which one do you use?)”

11/21/08 9:17 pm	Amanda said... Wow, what great info. I’ve always wondered what the difference is. So basically, a yam is a sweet potato and vice versa.
11/21/08 9:43 pm	Hannah said... Absolutely fascinating! I was actually wondering about this very recently… Thank you so much for clarifying things a bit.
11/21/08 9:54 pm	zoe said... Hi Amanda and Hannah, Yes, all of the sweet potatoes and “yams” we buy here in the States are all sweet potatoes. Crazy isn’t it! Zoë
11/22/08 12:32 am	char said... So you are a chef, a writer, a sculptor, a photographer, and definitely a scientist, too! (and more, I’m sure) You make the whole journey sound so fun… Thank you for sharing your findings with us!!! (I don’t care for potatoes, and yet I love sweet potatoes–now it all makes much more sense.) Enjoy a lovely Thanksgiving!
11/22/08 4:42 am	alienman said... Thank you for explaining all this. I have always wondered what the difference was and I thought I was one of few who did not know b/c I spent half my life outside the US. Haha. The purple yam is my favorite! It’s so rich and almost chewy like candy when baked. The sweet flavor blows me away. Yum, you’ve stirred some cravings in me
11/22/08 7:02 am	rachel said... That is really interesting. I really want to try a purple yam, I hope my Whole Foods has them.
11/22/08 10:16 am	cakebrain said... what a great post on the yam/sweet potato debate! I too like the purple yam. I always buy it at the Asian market. Really interesting recipes incorporating them too!
11/22/08 12:29 pm	Gaye said... Zoe In your article you said there was a real difference in the taste when using grated raw vegestables in cooking. But you didn’t say which you prefered. I want to know which one.
11/22/08 12:34 pm	zoe said... Hi Gaye, For the pudding I preferred the sweet potato, because the recipe is already quite sweet and the other two options made the pudding cloying for me. Ochen, however, liked the sweeter version! Thanks! Zoë
11/22/08 2:20 pm	Jesse said... What a fantastic experiment! Thank you for sharing this.
11/22/08 3:52 pm	The Sweet Potato vs. Yam Debate on APM’s Weekend America : Zoe Bakes \| dairyfactory.com said... [...] Here is the original post [...]
11/22/08 5:35 pm	Mike said... Did you happen to find a Japanese sweet potato?
11/22/08 8:49 pm	Diana @ AppetiteforChina said... Thanks for such an informative post. This is the first time I’ve seen someone do sweet potato pots de creme…but none came out better than the others?
11/22/08 10:31 pm	Joanna said... i have never seen a purple yam before!!! i’m so jealous!! i’m gonna go to whole foods and look for one.
11/22/08 11:44 pm	janelle said... Holy cow, wow. And some gorgeous pictures for this yammy rendezvous! Great job!
11/23/08 9:28 am	zoe said... Hi Mike, No Japanese sweet potatoes (or are they yams?) on this trip, but I’m now on a mission to try as many varieties as possible. Hi Diana, I’ll make it with the Jewel “yams” because of the color. The purple yam was our least favorite for this recipe, although we loved it in other things! Hi Joanna, You may need to seek out an Asian market to find the purple yam?? My whole foods only had the sweet potato “yams”. Thanks, Zoë
11/23/08 2:33 pm	ann said... The purple yam is a favorite of mine. I’m Filipina so I know it as ube. This type of yam is used in a lot of desserts. I’ve had it in ice cream, cake, jam, breads and other treats. If you’re in the Asian market again you should definitely pick up some ube ice cream. It’s so good! Also, if you ever have the chance you should try an ube cake from the Goldilocks bakery (located in California and Nevada).
11/23/08 7:43 pm	Saundra Shaver said... I buy purple potatoes at Trader Joes all the time. They are delicious, and purple is my favorite color, so it “fits” in my kitchen decor. Purple mashed potatoes are disarming… but oh so delicious!
11/23/08 9:12 pm	zoe said... Hi Ann, I’d love to try the ube ice cream, I’ve read about it but have never tried it before. I’ll keep my eyes peeled for it. Hi Saundra, You will love these yams, the color is like nothing I’ve ever seen before! Thanks, Zoë
11/23/08 9:44 pm	Sandy S said... Those purple yams are so beautiful! I haven’t seen anything like that in my neck of the woods, unfortunately, but I’ll live vicariously through yours. Great post!
11/24/08 11:42 am	Печени сладки картофи с пастет от черен боб « Кулинарно - в кухнята с Йоана said... [...] за сладките картофи от Zoe Bakes и се оказа, че има много видове. В София, обаче съм [...]
11/24/08 12:51 pm	Maris said... Sweet potato milkshake!? Zoe, you are my new hero.
11/24/08 5:08 pm	Aunt Else's Aebleskiver said... If these yams taste as beautiful as the photos, we are in for a treat! I’m going to try to find the purple ones.
11/24/08 9:03 pm	Sandie said... I’ve always wanted to incorporate more purple yams into our diet, but they’re so hard to come by around here! Love their purple color though, not to mention sweet flavor…they’re so disarming.
11/24/08 10:08 pm	zoe said... Hi Sandy, thanks! Hi Maris, It really was delicious. My boys ran around the neighborhood talking about it, because I got some calls from moms wanting the recipe! LOL. Hey Chad, I can’t wait to try your new line of aebleskivers! Hi Sandie, I totally agree and will be eating a lot of purple food from now on! Thanks, Zoë
11/24/08 10:28 pm	lady katherine said... Hi, I was a little shocked when you came by my blog. I am so excited to have purchased your book, too bad I can’t have it autographed.lol. I love it so far and been to the main site. I guess you saw where I linked to send other to see your book. Nice to see you in picture and I going to look around your blog. later.
11/25/08 7:30 pm	Sylvie, Rappahannock Cook & Kitchen Gardener said... Love the experiments and the posting of all the photos. Thank you. I grew three kinds of sweet potatoes this year, I’ll be on the look out for more kinds to grow -next year. Look at all those gorgeous colors. And they are nutritious and tasty too!
11/27/08 9:14 am	john larson said... HUH???…I don’t think this clarified ANYTHING (as you can tell be reading the comments)…what is a yam vs. a sweet potato?…how many varieties of both are there?…your confusing “from the top” picture makes it worse!
11/27/08 9:52 am	zoe said... Hi John, Sorry if you are still confused. There are certainly more profound studies on the subject available. I guess the bottom line is that for your Thanksgiving recipes or any other, it doesn’t really matter which tuber you pick! Have a very Happy Thanksgiving! Zoë
11/29/08 4:53 am	RYErnest said... Nice post u have here Added to my RSS reader
12/1/08 11:43 pm	BBD#14 - Purple fingerling potato bread « Toxo Bread said... [...] about purple, like an intense purple yam [...]
12/4/08 6:42 pm	Ten Weeks of Roasting and Grilling Filet's AF 10-Week Challenge - Page 5 - AFboard said... [...] may think you are eating yam when you are eating sweet potatos: The Sweet Potato vs. Yam Debate on “Weekend America” (which one do you use?) : Zoe Bakes The difference is huge because the GI index of sweet potatoes is medium and that of yams is low. [...]
12/6/08 12:22 pm	Sweet Potato and Yam Casserole \| The Peanut Butter Boy said... [...] and Google and Wikipedia actually added to the confusion. The definitive answer can be found here: The Sweet Potato vs Yam Debate. While technically both are sweet potatoes, I’m still calling this the Sweet Potato and Yam [...]
12/12/08 5:32 pm	alex said... save to my Bookmarks
12/24/08 12:00 pm	Eating Healthy Without Being Wealthy: Sweet Potatoes and Yams \| Greener Pastures: Personal Finance said... [...] According to Zoe at Zoe Bakes, [...]
02/1/09 11:05 am	Тимур said... Эх… Вы бы знали что про Вас пишут в других блогах
02/22/09 12:42 am	A Side Note « In Good Taste said... [...] subtle differences between the two. Even though we use the terms interchangeably, in actuality the sweet potatoes and yams that we find here in the US are actually all sweet potatoes. Yams, of which there are about 200 varieties do not grow in the States but were first identified [...]
02/23/09 7:38 am	Gwinnett International Farmer’s Market « Food Near Snellville said... [...] on. I will sometimes shop this Farmer’s market because they are a good and cheap source of asian yams and kimchi. Also, if you really want the small single serving size of white rice, in microwave [...]
02/23/09 7:25 pm	tex said... Yams do not have vitamin A like sweet potatoes.
02/24/09 2:01 pm	Rollin Hetwall "Woody Spuds" potato perfection said... Hi, I wanted to thank Zoe and ask where I could find grower/shipper of these sweetest sweet purple potatoes
02/25/09 7:04 am	zoe said... Hi Rollin, This is the market where I find the purple yams. You can call them and see if they will tell you where they get them??? Shuang Hur Supermarket 2710 Nicollet Ave Minneapolis, MN 55408-1630 Phone: (612) 872-8606 Good luck! Zoë
03/16/09 8:01 pm	gery said... i think i recognise the yampi yampi as a type of yam used for hakka chinese savory dishes. it’s cooked with fermented red bean paste and it turns out a little powdery and mushy. the purple yam is used for a type of teochew chinese sweet yam paste with gingko nuts. and as ann mentioned above, in south east asia it’s generally called an ube.
04/13/09 1:12 am	Jamie said... Correction: Yams are tubers, Sweet Potatos are “roots” http://plantanswers.tamu.edu/vegetables/sweetpotato.html
04/24/09 8:46 pm	Yams vs. Sweet Potatoes « FoodMayhem said... [...] For the difference between yams and sweet potatoes, check out Zoe Bakes here. [...]
05/14/09 5:34 am	chau said... Hi, I’m just wondering how you determined that your yam specimens are “authentic?” Is it b/c the market staff told you so? If so, I’d take that info w/a grain of salt, b/c I’m asian and I know many times the translation of the items at the asian markets are incorrect. I think almost all of the samples here are different varieties of sweet potatoes, except the hairy one in the bottom right corner of the 1st pic. The purple sweet potato you have is often called “Okinawan s.p.” or “Hawaiian s.p.”. I don’t know about yam greens, but s.p. greens are often eaten in Vietnamese cuisine. Growing up, my grandma grew the purple s.p. (although the pigment isn’t as deep purple as the ones sold at the market), and we’d often eat the greens.
05/14/09 6:06 am	zoe said... Hi Chau, It is indeed hard to be sure but I think this purple yam is an “ube,” which is an Asian yam, not a sweet potato. But, like you said, I’m relying on the people at the market to tell me. Were the purple sweet potatoes that your grandma grew crazy sweet? This one tastes like I added sugar to it. Thank you! Zoë
05/14/09 5:32 pm	chau said... Hi Zoe. The purple s.p. my granny grew were quite sweet but still not as sweet or as deep purple as the ones we’d get at the market. That aside, the flesh texture, flavor, skin color and root shape are the same. I noticed that gernerally the deeper the purple, the sweeter the s.p., and the slight differences in color and sweetness may be just natural variations w/in the same cultivar. So I’d presume the more “superior” variety was selected for commercial sale. Mine looked somewhat like this (though the pigment was more purple than reddish here): http://www.flickr.com/photos/8442333@N05/2378905728/ After a quick “research” on the net, I feel there’s a slight confusion between purple s.p. and ube (& sometimes even w/taro) among a few consumers (I don’t mean you ). I believe this is what “real” ube looks like: http://bakerri.blogspot.com/2008/02/ube-cupcakes.html http://www.marketmanila.com/archives/ube-kinampay-purple-yam I hope we’ve come close to solving this mystery
05/14/09 8:14 pm	zoe said... Hi Chau, Thank you for the wonderful links. I think I have to do more research, perhaps a trip to Vietnam to see the real deal! It is fascinating. Zoë
05/15/09 6:42 pm	chau said... My pleasure, Zoe
05/16/09 9:42 pm	Sean said... ZOE, Hello, thanks for the article it was great to find someone that addressed this. I live in Mexico and have found what I believe is the Asian Sweet Yam, can you tell me the interior color of this? 2nd) If you were to look at the nutritional facts for a sweet potato vs a yam on any given US nutrition website it shows two different nutritional facts. So are they actually showing the nutritional facts for an American Yam (SP) and a “white” sweet potato or are they using actual yam vs sweet potato. Thanks. Sean
05/20/09 1:45 pm	Sandi said... I live in Hawaii where we have an abundance of “yams” and “sweet potatoes,” due to the wonderful mix of Pacific Island, Asian and other cultures. The purple “yamtato” you have pictured is called Okinawan Sweet Potato in Hawaii and is made into wonderful desserts. Most famously is the haupia (coconut) sweet potato pie. I recently had a dish that was Okinawan sweet potatoes and bananas. It was like a very thin pudding. Babies in Hawaii love mashed Okinawan sweet potatoes and older keiki (children) like Okinawan sweet potato fries.
07/8/09 4:21 pm	Joy said... I found this searching for recipes for some purple yams (ube) that I accidentally bought at the Farmer’s Market. Great info and I won’t return them now that I know how good they are!
09/9/09 8:10 pm	James G Sack said... I think it would be useful to people who stumble upon your page in search of a definitive resolution of the puzzle (“what’s the difference ..?”) if you updated your main text and picture captions to point out which (if any) of your illustrations is a true yam. And perhaps even to emphasize it, to comment [if correct] that unless identified as true yam, most of your examples are sweet potatoes even if they are commonly called/labeled yams. Nevertheless, thanks for the interesting article.
09/9/09 8:48 pm	zoe said... Thank you James, I’ve gotten that feedback before and will try to redo the photo at some point to make it clearer! Best, Zoë
09/22/09 9:54 pm	Chinese Vegetarian Recipes said... I thought that they are not yams but sweet potatoes, too. But that’s not important as long as you know what you are looking for. For me, I have learned how many kinds available out there and what they can be made into. Thanks, Zoe.
11/24/09 2:41 pm	Foodista Blog - Sweet Potatoes or Yams? said... [...] made with sweet potatoes. Did you know that what we call yams are really sweet potatoes? It’s an accident that we ended up this way to begin [...]
12/6/09 8:25 pm	Eileen Jackson said... I’m so glad you cleared this up for me. I’m 67 and when I was young sweet potatoes were red and narrow. Yams were rotund and yellowish. To my mother it was clear. Then suddenly I woke up one day about 30 years later and suddenly those little thin sweet red tubers were labled “Yams” in the store. And Sweet Potatoes were rotund and yellowish. I knew something was seriously amiss but I just didn’t know what. Thanks for straightening it all out for me.
01/1/10 8:21 pm	Sylvia said... It’s really nice to know the difference in all of these! To be completely honest, I wasn’t aware that there was a difference in a yam and sweet potato, I thought they were interchangeable. I’m so glad the great debate is clarified! And to answer your question, I use a different one every year! -Sylvia
01/26/10 4:49 pm	Ruth B said... So… what’s the difference? Which is which? (I don’t understand the photo label — from the top, ok, got that, the top one is labelled. But the others? Right to left? Counterclockwise?) I did a search on Google for the difference, this blog was one of the top returns, but this doesn’t really tell the difference between them. Lovely photos, though, and I like the recipe offerings.