Abstract: This disclosure describes a biotechnological method for producing rebaudioside M (Reb M), using recombinantly produced glucosyltransferases, which can be carried out in a single reaction vessel using two glucosyltransferases and a uridine diphosphate glucose (UDPG) regenerating system. The method can be used to produce the commercially desirable Reb M from rubusoside, stevioside, or rebaudioside A (Reb A), which are all naturally more abundant steviol glycosides but with commercially less desirable properties.