During a trip to a Caribbean grocery near my home to find some new foods to experiment with, I found a wide selection of yams. Jamaica, Dominican, Ghana, etc. I chose a Ghana yam to take home and try to cook by itself to see how it tasted on its own. I did my research and found that yam skin is not edible, nor is its raw flesh. So I peeled the yam, cut it into pieces, and boiled it for quite a long time, about 45 minutes to be extra sure, and they were nice and soft. I took a small bite and found the texture and flavor to be much like white potato. So I then ate a larger piece. After I had swallowed, I realized I had a slight, but noticeable, lingering bitter taste in my mouth. I panicked and did some more Googling and found that the wild variety in Africa contains high concentrations of alkaloids and are traditionally soaked and fermented for several days and/or boiled in several changes of water. I immediately discarded all the remaining cooked yam. I would assume what is sold in the grocery store would be cultivated rather than foraged, but is it possible they were actually wild? Or was I just being paranoid and it is normal for yams to have a slightly bitter taste? Any insight is appreciated, thanks!