Lignin, the second most abundant biopolymer in earth, represents nature’s largest carbon sources, has high polydispersity and uncertain reactivity, that limit efficient modification/degradation and use of products obtained. In order to decrease by mechanochemical means the average molecular mass and polydispersity of lignin fragments of the CIMV organosolv lignin named Biolignin™, we applied a sodium hydroxide-assisted planetary ball milling process. Experimental conditions were first optimized on purified Biolignin™ then to Biolignin™ without prior purification in 20 mL jars before applying it successfully to a 500 mL planetary ball milling apparatus. Extensive, quantitative HSQC NMR, IR and GPC studies, overtaken supported our three most important findings: reduction of the needed quantity of sodium hydroxide of 75 % compared to the literature, obtention of halve (-51 %) the occurrence of β-O-4’ linkages in lignin fragment, an optimum of 14 wt% of moisture is useful in the degradation process.