Go to an Asian store. They have very nice purple sweet potatoes.

dcarch

As far as I know, they're just sometimes white inside. I think your best bet is to ask the produce guy to cut one open for you. :) I don't know this, but my guess is that if one is white the whole crop is.

Thanks folks. No Asian stores here. LOL, I wonder how many the produce guy/gal will be willing to cut open for me.

Another thought, does age make them more white? Now that I've used two they seem sort of old inside. Sure not like the orange ones that are practically pudding after baking. These are dry, fibrousy, starchy looking.

Find a way to grow your own.

You get your purple sweet potatoes, you can also cook sweet potato greens. Very delicious.

dcarch

There are 2 purple yam/sweet potato varieties which are actually not related to one another. These are both separate from the Peruvian purple potato, which is a true potato.

- Dioscorea alata: The tubers are usually bright lavender in color, hence the common name "purple yam", but they may sometimes be white. To thoroughly confuse people, they are sometimes grown on Okinawa (see below) as is the other purple variety. Cooking with this retains the bright lavender color.

- Ipomoea batatas cv. Ayamurasaki, aka Okinawa sweet potato: These are a duller purple. When cooked it turns a brownish-purple shade. They aren't very sweet so recipes for standard pumpkin pie may need some adjustment.

HTH.

If you're a buyer, and are sweet and friendly, they'll probably cut them all for you, but if two or three are white, you can probably assume the whole lot is.

Your age theory is possible, but I did a search and can't find any mention of it.

One thing to remember is that the purple ones are yams, not sweet potatoes, whereas almost everywhere in the U.S. the tubers labelled "yams" really are a variety of sweet potato and only called "yams" because people brought their old name to this new-to-them vegetable. Real yams are more in the white/yellow/pink/purple family than the orange/red family, and aren't as soft and sweet as sweet potatoes. The purple ones, at least, are chock full of antioxidants which has led to their growing popularity.

I confess I'm thoroughly confused as to the difference between yams and sweet potatoes. Websites from cooking, gardening and University Dept. of Agriculture or Horticulture really disagree. SP are sweeter, no, yams are. Yams are starchy and scaly. One is dry, no, the other one is. Yikes.

They're just different plants. The Dept of Ag should be accurate. It confuses things that we call some sweet potatoes "yams" popularly. How do you know if they're talking about taxonomical yams or yams by convention? It's apparently the law nowadays that the yams by convention (dating back to Africans using their words to describe sweet potato tubers (the plants are very different looking)), it's the law that they have to also say "sweet potato". That doesn't mean that all the grocers know that and comply.

Here's a reference that's easy to read.

OTOH, I google imagesed "real yam recipes" and got pictures almost exclusively of sweet potato dishes.

Thanks plllog. If it helps anyone else I was in my local Zehrs (ONtario, Canada) yesterday and they will order in Purple Sweeties. They come from Jamaica and will be in a mesh bag.