A process for producing a thermoplastic molding composition comprising at least one thermoplastic copolymer A and at least one graft copolymer B, comprising the following steps: a) precipitating the at least one graft copolymer B after an emulsion polymerization, by adding a precipitation solution; b) dewatering the precipitated graft copolymer B, preferably by centrifugation and/or filtration, affording a dewatered graft copolymer B having a water content of less than or equal to 50% by weight; c) continuously drying the dewatered graft copolymer B, wherein a drying gas and the dewatered graft copolymer B are supplied, the dewatered graft copolymer B is moved by the drying gas and forms a fluidized bed, the drying gas has an feed temperature T G,zu in the range from 50°C to 160°C, and dried graft copolymer B and an off-gas are discharged, wherein i. a starting temperature T ein of the fluidized bed is measured at the feed of the dewatered graft copolymer B, ii. an end temperature T aus of the fluidized bed is measured at the removal of the dried graft copolymer B and/or of the off-gas, iii. a difference ΔT ist between the measured end temperature T aus and the measured starting temperature T ein is calculated and the difference ΔT ist is compared with a nominal value ΔT soll which is in particular at least 2°C, and iv. the end temperature T aus is adjusted by - increasing a mass flow of supplied drying gas and/or the feed temperature T G,zu of the drying gas when the difference ΔT ist is smaller than the nominal value ΔT soll or - decreasing a mass flow of supplied drying gas and/or the feed temperature T G,zu of the drying gas when the difference ΔT ist is greater than the nominal value ΔT soll; d) optionally mixing of the thermoplastic copolymer A, the dried graft copolymer B, optionally further polymeric component(s) C, and optionally further component(s) K. a) precipitating the at least one graft copolymer B after an emulsion polymerization, by adding a precipitation solution; b) dewatering the precipitated graft copolymer B, preferably by centrifugation and/or filtration, affording a dewatered graft copolymer B having a water content of less than or equal to 50% by weight; c) continuously drying the dewatered graft copolymer B, wherein a drying gas and the dewatered graft copolymer B are supplied, the dewatered graft copolymer B is moved by the drying gas and forms a fluidized bed, the drying gas has an feed temperature T G,zu in the range from 50°C to 160°C, and dried graft copolymer B and an off-gas are discharged, wherein i. a starting temperature T ein of the fluidized bed is measured at the feed of the dewatered graft copolymer B, ii. an end temperature T aus of the fluidized bed is measured at the removal of the dried graft copolymer B and/or of the off-gas, iii. a difference ΔT ist between the measured end temperature T aus and the measured starting temperature T ein is calculated and the difference ΔT ist is compared with a nominal value ΔT soll which is in particular at least 2°C, and iv. the end temperature T aus is adjusted by - increasing a mass flow of supplied drying gas and/or the feed temperature T G,zu of the drying gas when the difference ΔT ist is smaller than the nominal value ΔT soll or - decreasing a mass flow of supplied drying gas and/or the feed temperature T G,zu of the drying gas when the difference ΔT ist is greater than the nominal value ΔT soll; i. a starting temperature T ein of the fluidized bed is measured at the feed of the dewatered graft copolymer B, ii. an end temperature T aus of the fluidized bed is measured at the removal of the dried graft copolymer B and/or of the off-gas, iii. a difference ΔT ist between the measured end temperature T aus and the measured starting temperature T ein is calculated and the difference ΔT ist is compared with a nominal value ΔT soll which is in particular at least 2°C, and iv. the end temperature T aus is adjusted by - increasing a mass flow of supplied drying gas and/or the feed temperature T G,zu of the drying gas when the difference ΔT ist is smaller than the nominal value ΔT soll or - decreasing a mass flow of supplied drying gas and/or the feed temperature T G,zu of the drying gas when the difference ΔT ist is greater than the nominal value ΔT soll; - increasing a mass flow of supplied drying gas and/or the feed temperature T G,zu of the drying gas when the difference ΔT ist is smaller than the nominal value ΔT soll or - decreasing a mass flow of supplied drying gas and/or the feed temperature T G,zu of the drying gas when the difference ΔT ist is greater than the nominal value ΔT soll; d) optionally mixing of the thermoplastic copolymer A, the dried graft copolymer B, optionally further polymeric component(s) C, and optionally further component(s) K.