Abstract: The most commonly occurring biopolymer, cellulose, is typically extracted from plants and trees after harsh chemical processing. Bacterial cellulose (BC), produced by a simple fermentation process using sugar-rich media, is superior to plant cellulose owing to its purity, porosity, crystallinity, water holding capacity, and nanofibrous nature. However, the application of BC is still limited owing to the need for application-specific tunability. The benchtop production of BC in a controlled environment allows in situ tunability of its structure and morphology during synthesis (pre-production and during-production), in addition to the conventional post-production strategies. A review of literature on various modification strategies with an emphasis on in situ modifications is presented and their capability to alter crystallinity, porosity, nanofiber dimensions, mechanical properties, and yield are discussed in detail. This review concludes with a section dedicated to the future scope of applications of BC which can be primarily enabled by in situ modifications. Graphic abstract: [Figure not available: see fulltext.] © 2021, The Author(s), under exclusive licence to Springer Nature B.V.