Abstract: A method for growth of group III metal nitride crystals includes providing a manifold comprising including one or more transfer vessels, a source vessel containing a condensable mineralizer composition, and a receiving vessel, chilling a metallic surface within the one or more transfer vessels, the metallic surface comprising a composition that does not form a reaction product when exposed to the condensable mineralizer composition, transferring a quantity of the condensable mineralizer composition to the one or more transfer vessels via a vapor phase and causing condensation of the condensable mineralizer composition within the one or more transfer vessels, measuring the quantity of the condensable mineralizer composition within the at least one transfer vessel, transferring at least a portion of the condensable mineralizer composition to the receiving vessel, and forming at least a portion of a group III metal nitride boule by an ammonothermal crystal growth process that comprises exposing a seed crystal to