Irvine, California-based Diedrich Coffee, a roaster, retailer and wholesaler of specialty grade coffee, has announced the appointment of Roger J. Stewart as director of sales, Office Coffee Services (OCS). Stewart comes to Diedrich Coffee from USRefresh, in Boston, where he was senior VP, operations, responsible for their office coffee service and vending business. Previously, he was president of AAA Coffee Service and VP, market development for US Office Products.