tBacterial cellulose (BC) nanoribbons were partially acetylated by a simple direct solvent-free route cat-alyzed by citric acid. The assay of reaction conditions within chosen intervals (i.e. esterification time(0.5?7 h), catalyst content (0.08?1.01 mmol/mmol AGU), and temperature (90?140◦C)), illustrated theflexibility of the methodology proposed, with reaction variables which can be conveniently manipulatedto acetylate BC to the required degree of substitution (DS) within the 0.20?0.73 interval. Within this DSinterval, characterization results indicated a surface-only process in which acetylated bacterial cellulosewith tunable DS, preserved fibrous structure and increased hydrophobicity could be easily obtained. Thefeasibility of reusing the catalyst/excess acylant in view of potential scale-up was also illustrated.