The anisotropic behavior of bulk solids is significant for many applications in bulk solids handling like consolidation processes or silo design. A new powder tester has been developed to measure the unconfined yield strength in the uniaxial direction, which means consolidation and strength measurement in the same direction, as well as to measure the anisotropic unconfined yield strength in the biaxial direction, which means consolidation and strength measurement in orthogonal directions. In the anisotropy tester the consolidation stress is applied through movable sidewalls in the horizontal direction for measuring the anisotropic unconfined yield strength and in the vertical direction for measuring the uniaxial unconfined yield strength. The friction between the walls and the bulk solid is minimized by flexible membranes that deform uniformly with the specimen. After the consolidation step all sidewalls are removed and the freestanding specimen can be stressed in the vertical direction until failure occurs. The ratio between the anisotropic and the uniaxial unconfined yield strength yields the intensity of the anisotropic consolidation behavior. This ratio has been measured for different bulk solids and consolidation stresses sigma 1 ranging between 20 and 250kPa. The design of the tester as well as the experimental results with three different bulk solids are presented.