So when I looked it up I found that the main distinguishing factor is that a sweet potato tends to have pointed ends, and yams tend to have rough scaly skin.
I wanted more of answer than that, so I decided to buy them both and check it out for myself.
The other thing that fueled this experiment is a new local restaurant called The Blue Lemon. I am addicted to their "Sweet Potato Fries." They are delicious and I order them every time I eat there. I wanted to try to replicate them, since I like deconstructing my favorite dishes at home.
The first thing I did was peel both vegetables, and what did I discover? They aren't even the same color! Um, okay that's the first obvious difference between the two. (Although I did read that yams vary in color from white to ivory to yellow to purple).
The other thing I discovered during this experiment is that those Sweet Potato Fries that I've been orderin' and lovin' are not made out of sweet potatoes! They are yams.
I actually liked both the yam fries and the sweet potato fries. I think I lean in favor of the yam fries (but I think I'll keep calling them sweet potato fries too. Old habits die hard.)
Peel and cut into fry fry sized slices. Drizzle with olive oil or vegetable oil, then sprinkle with cumin, coriander, and salt. When I made these I just did one of each kind of potato. It was a late night snack for just Brian and I. If making for a family I would probably cook 3-4 of them.
Bake in the oven at 400 degrees until soft, and they start to brown. Just watch them, but it took mine about 30 minutes, and they came out perfect!
3 T. bbq sauce
3 T. mayonnaise
1 tsp. lemon juice