Disclosed herein are systems and methods for heating alane etherate compositions for producing microcrystalline alpha alane. An exemplary heating method comprises introducing a preheated solvent into the alane etherate composition and rapidly stirring to effectuate rapid heating of the composition without the need to heat the reactor walls. In this way, the alane etherate composition can be heated while also reducing the risk of decomposition. In further embodiments, a two-stage reactor can be employed for producing alpha alane, wherein the heating occurs in the second stage.