A method of manufacturing a wind turbine rotor blade includes, in one embodiment, the steps of providing a core, and applying at least one reinforcing skin to the core to form a blade subassembly. Each reinforcing skin is formed from a mat of reinforcing fibers. The method also includes applying a micro-porous membrane over the at least one reinforcing skin, applying a vacuum film over the micro-porous membrane, introducing a polymeric resin to the core, infusing the resin through the core and through the at least one reinforcing skin by applying a vacuum to the blade assembly, and curing the resin to form the rotor blade.