Yams have a cylindrical shape with blackish or brown, bark-like skin and white, purple, or reddish flesh.

Are yams white or orange?

“Most of the so-called yams you see in American grocery stores are actually orange-fleshed sweet potatoes,” explains Mary-Frances Heck, author of new cookbook Sweet Potatoes (and former BA staffer).

Why is my yam white?

The white substance that sometimes seeps out of sliced sweet potatoes is a completely normal sap, a mixture of sugar and starch. It is not harmful in any way and is completely safe to eat. If you’d like to learn more about the white ooze common in sweet potatoes, keep reading.