What happened to my pie?

I was making a sweet potato pie, following this recipe:

Alton Brown’s Sweet Potato Pie

If you don’t want to bother with the link, it goes like this: Cube some sweet potatoes and steam them. Mash them, then mix in plain yogurt, brown sugar, spices, and eggs; pour into a pie shell, bake, top with pecans and maple syrup. Sounds easy and good, yes?

I should mention that I’d never really messed with sweet potatoes from scratch before. The SPs I got from my grocery store were, when peeled, not a jolly orange color but had white flesh. After they were cooked, they had gone a faint green-gray hue. “Yuck,” I said, but pressed on with the recipe, adding the yogurt, sugar, and spices. Just before I added the eggs, I tasted the mixture.

Blech! It was not very sweet at all, and it had an unpleasantly mealy texture. No way was I going to serve someone a pie that tasted like that (not to mention the ugly grayish rotten-potato hue). I threw the whole revolting mess away and ran to the store for some canned pumpkin.

What did I do wrong? And does anyone have recipes/tips for good sweet potato pie?

That recipe is pretty much what goes into pumpkin pie, except for the yogurt.

I wonder if you bought yams instead of sweet potatoes. I’ve never cooked yams, but I read somewhere some varieties are an off-white color under the peel.

Good idea not to serve it. If it didn’t taste good before you baked it, it wouldn’t taste good after.

Hmmm, my guess is you got something other than sweet potatos. Maybe they were mismarked at the store?

Sweet potatoes, when raw, are often a bit paler than when cooked. But when cooked they do get that lovely orange color - the same as the canned ones.

So that’s my guess. Blame the taters.