The invention refers to a bale forming apparatus and a bale forming method for forming a bale from loose material, in particular from crop material. A bale forming member is pivoted while the bale is formed. A retaining device controls the pivoting of the bale forming member. A hydraulic system (14, 22, 24, 28.1, 28.2) of the retaining device contains a hydraulic fluid. A flow restricting device restricts a flow of the fluid in the hydraulic system (14, 22, 24, 28.1, 28.2). According to the invention a field generator (27) generates a magnetic field (29.1, 29.2, ... ) in a part (28.1, 28.2) of the hydraulic system (14, 22, 24, 28.1, 28.2). This magnetic field (29.1, 29.2, ... ) changes the viscosity of a magneto-rheological fluid in the hydraulic system (14, 22, 24, 28.1, 28.2).
