Who knew? We field a ton of questions here every day and by far the most disagreed on answers come from the, "What's the difference between a sweet potato and a yam...?" debate.
The biggest problem with this question is that the industry and local perception has skewed the facts and we now accept an untruth as fact! Would you be surprised if I told you that all those times you thought you were eating yams, you were likely eating a sweet potato, and that you probably haven't ever actually had a true yam? Yet, yam and sweet potato do mean different things in grocery stores. While much of the confusion stems from these names being used interchangeably in U.S. markets and in recipes, sweet potatoes and yams are actually two distinct and very different vegetables. Yams are native to Africa and Asia, with the majority of the crop coming from Africa. They are related to lilies, and can be as small as a regular potato or ridiculously jumbo in size. Yams have a cylindrical shape with blackish or brown, bark-like skin and white, purple or reddish flesh. Compared to sweet potatoes, yams are starchier and drier. They are carried in more grocery stores these day, but your best chance of finding them are in international and specialty markets.
Here's an interesting little history lesson to explain why there's so much confusion. There are two types of sweet potatoes - "firm" and "soft." The firm variety was the first to be produced in the U.S., so when "soft" sweet potatoes began to be produced commercially, there was a need to differentiate it from its firm counterpart. Since the "soft" sweet potatoes slightly resembled true yams, they picked up the name and became what you see labeled as "yams" in most U.S. grocery stores.
- Soft sweet potato with a copper skin and deep orange flesh.
- Firm sweet potato with golden skin and lighter flesh.
So, for ordering purposes here at Peddler's Son sweet potatoes are white fleshed and yams are orange fleshed.