Methods of manufacturing bulked continuous carpet filament which, in various embodiments, comprise: (A) grinding recycled PET bottles into a group of flakes; (B) washing the flakes; (C) identifying and removing impurities, including impure flakes, from the group of flakes; (D) adding one or more color concentrates to the flakes; (E) passing the group of flakes through an MRS extruder (400) while maintaining the pressure within the MRS portion (420) of the MRS extruder (400) below about 25 millibars; (F) passing the resulting polymer melt through at least one filter (450) having a micron rating of less than about 50 microns; and (G) forming the recycled polymer into bulked continuous carpet filament that consists essentially of recycled PET.