An extruder (100) for comestible material comprises a tubular barrel (104) and one or more elongated, axially rotatable, helically flighted screws (120, 122) within the barrel (104), where the barrel (104) has a delivery opening (114a). The extruder barrel (104) is equipped with an assembly (22) for delivery of fluid to the interior thereof, including a static mixing section (54) operable to blend the steam and water to create a blended mixture； the blended mixture is delivered to the barrel opening (114a) by means of a conveying assembly (84, 86) having a pipe assembly (86) with an outlet in communication with the barrel opening (114a)； the pipe assembly (86) and opening (114a) have diameters less than maximum internal diameter of the static mixer casing (72).
