For a while now I’ve been trying to figure out how to make desserts with purple sweet potatoes without having the desserts turn a dull gray or even sometimes a dark green.
I simply couldn’t figure it out. I scoured the internet for answers, read the posts and comments on the purple sweet potato cakes I saw on other food blogs, and came up with nothing.
Well this weekend I found the answer. Sort of. I believe I was using the wrong kind of purple sweet potato. In all the food blog posts I read, the purple sweet potatoes were thin and the skin had a purplish/pink hue to it. The purple sweet potatoes I knew of and buy from Ranch 99 and Zion market have a white/gray skin and are rounder and thicker.
This weekend while shopping at Nijiya, I came across Japanese Okinawan purple sweet potatoes. They were thin and the skin had a dark pinkish/purple hue. They resembled the ones I saw on the posts, so I bought a few to test them out.
These are the ones I bought this weekend. Unfortunately, I don’t have pictures of the white/gray skin ones but you can view a picture here. 
Sure enough, these purple potatoes maintained a pretty color when mixed into my cake batter. They did lose their vibrant purple color, but they turned a pretty pink, like the cakes I saw on other posts, rather than a dull gray.
I’m not sure what type of purple sweet potato I was using before. I tried looking it up, but I didn’t find any answers. Even more confusing, when I looked up images of Okinawan sweet potatoes, I found images of the white/gray skin ones I had been using previously.
Other than the appearance, I noticed some other slight differences between the two potatoes. When you cut them open, they both are purple inside and when steamed, they become an even more vibrant purple. However, the white/gray skinned potato is starchier and sweeter compared to the skinny ones.
For this chiffon cake, I left little bits of purple sweet potato in the batter, which made the cake retain more of a sweet potato flavor. Next time I think I will completely puree the potatoes so I have just a pink cake.
This cake came out lovely. It was probably the most perfect chiffon cake I’ve made to date. Sometimes the cakes will get a little stuck and not come out easily. Or sometimes they are slightly overbaked. This one was perfect. Baked just the right amount of time and it slid out of the pan quite easily and I didn’t lose any of the cake in the pan. I used this Wilton Pan.
It was so light and soft and the perfect amount of sweetness. I only wish this cake wasn’t so tiny. I devoured about half of it myself in one sitting!
I used a recipe I found on Little House and followed it exactly, except for the fact that I didn’t completely blend the sweet potato in a food processor. Instead, after I steamed it, I just used a whisk to mash it, leaving little lumps. Usually, I make some tweaks to a recipe, but this one was perfect.
Hi, I am unable to view the recipe on the link you provided. Would you kindly post the recipe here pls?
unfortunately, i dont have the recipe. I had just used that person’s, and always referred to the blog post, which unfortunately isn’t loading.
You always make one of the most creative chiffon cakes 🙂
I love chiffon cakes, so I love trying out new flavors.
I love purple sweet potatoes, especially the ones with the whitish skin and bright purple flesh. I have been thinking about using them for a dessert, but I noticed that they’re very starchy indeed. I’m so glad to have found your beautiful chiffon cake, and now I know which purple sweet potato to look for when I want to create a sweet treat.
I think the whitish skin ones may be a bit too starchy to bake with. Well it’s possible I think, but you’ll probably have to add water/oil for moisture. The biggest problem is that they turn a gray when mixed with the egg yolks and then they turn a green if you let the batter sit out too long. These ones with the purplish skin are less starchy, still a pretty purple and bake without turning gray.
Hello! Long time ;] Is purple sweet potato the same thing as ube?
Welcome back from your trip! No, ube is a purple yam, which I have yet to find fresh versions of here. Only found frozen ones. Purple sweet potato has a diff texture and taste.