The invention relates to a method for obtaining 1-kestose on an industrial scale, using a recombinant fructosyltransferase (FTF) isolated from Festuca arundinacea, constitutively expressed in a non saccharolytic yeast host. According to the invention, the recombinant FTF of the sucrose:sucrose 1-fructosyltransferase (1-SSTrec) type is produced in a constitutive and stable manner and in high yields, both in the supernatant and in the cell sediment of the culture of a strain of