The double bag vacuum infusion process of the present invention provides a low cost method for producing complex composite assemblies without an autoclave. It also enables the production of highly innovative structures. The quality of the composites produced using such an infusion process are comparable to composites made using prepregs, hand layup or fiber placement, and autoclave curing. Double bagging provides vacuum integrity, controls bag relaxation while flow media controls the flow front to allow high quality aerospace-grade products.