A Mortar Delivery System is described. The Mortar Delivery System provides precise control of the delivery and application of mortar in addition to the mixing and tempering of mortar. Such control eliminates the use of a hand trowel in brick, block and stone laying applications. Sensing and control are integrated with the Mortar Delivery System to make it an important element of a robotic brick laying system. The Mortar Delivery System contains sensors to measure mortar viscosity and workability, mortar flow rate, and mortar nozzle pressure. The data from the Mortar Delivery System sensors can be used to change the rotational speed of the shear blades, change the amount of water being used for mixing or tempering, and change the delivery speed of the mortar. Such changes result in precise control of mortar that is in turn suitable for automated or semi-automated building processes.