Abstract: Methods are disclosed for generating aerial mycelium, such as mycological material comprising solely mycelia from depleted substrate or depleted and rejuvenated substrate. Alternatively, methods are disclosed for generating mycelia and mushrooms from depleted substrate or depleted and rejuvenated substrate. Alternative methods are disclosed for generating differentiated mycelium materials using depleted substrate or depleted and rejuvenated substrate. The mycelia products that are generated can be used in the food industry (e.g., as a meat analog) and in other industries, such as textiles, packaging, and others. The present invention provides systems and methods for generating mycelia that are repeatable and energy efficient, while providing consistently high quality and quantity mycelium-based products.