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 steam and water to create a blended mixture; the blended mixture is delivered to the barrel opening (114a) by 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).