Identification

• The Merriam Webster Online Dictionary defines a yam as "the edible starchy tuberous root of various plants (genus Dioscorea of the family Dioscoreaceae)." Most people think of yams as the orange-colored sweet potato commonly gracing the Thanksgiving dinner table, but some 200 different varieties of yams exist, bearing a multitude of different hues.
  
  

Curing

• Curing is the process of drying the skin of the yam, healing small wounds and toughening the root to better withstand storage for a significant period of time. Curing takes place immediately after harvesting, using high heat and humidity under a cover to trap yam-generated heat and moisture. The technique may require anywhere from one to four days. Many yams are also cured with kiln-drying.
  
  

Effects

• In some instances, yams may be placed in a stack, unwashed, as dirt helps retain humidity, and covered with canvas to enhance the curing process. "Great care is needed when handling the tubers after they have been cured so that new injuries are not made," writes the USP Institute for Research, Extension and Training in Agriculture.