Foam test for double metal cyanide-catalyzed polyols

Double metal cyanide-catalyzed polyols are made by an improved process in which a starter is continuously added during polymerization of the epoxide. The process includes a continuously added starter (Sc), and optionally, an initially charged starter (Si). The continuously added starter comprises at least about 2 equivalent percent of the total starter used. The process enables the use of water and low molecular weight polyol starters in DMC-catalyzed polyol synthesis. In addition, the process gives polyether polyols having reduced levels of high molecular weight polyol tail, which can adversely affect polyurethane foam processing.