Abstract: Efforts to recycle organic waste using black soldier fly (BSF) larvae into high-quality alternative proteiningredients in animal feeds and organic fertilizers have gained momentum worldwide. However, thereis limited information on waste manipulation to increase nutrient retention for enhanced larval perfor-mance and frass fertilizer quality. In the present study, brewer’s spent grain with a carbon to nitrogen (C/N) ratio of 11 (control) was amended with sawdust to obtain substrat...