By Leslie Josephs The Wall Street Journal March 18, 2012 Coffee roasters are battling for both market share and raw materials as supplies of coveted handpicked beans dwindle. The industry will be abuzz over this and other issues facing the changing marketplace at the National Coffee Association's annual conference this week. Starting Thursday, executives from roasters such as Starbucks Corp., SBUX +0.26% Maxwell House-maker Kraft Foods Inc., KFT +0.21% and J.M. Smucker Co., SJM +0.41% which produces Folgers, will join growers groups, commodity trade houses and banks at the Charleston, S.C., meeting. Another topic of discussion around the table will be the explosive growth of single-cup brewing machines. Starbucks is at the center of the single-serve frenzy. It currently sells its coffee in K-Cup pods that work with the Keurig machine. The machines, made by Green Mountain Coffee oasters ...