'nonfermentable' originates from English, specifically the negative prefix 'non-' and the adjective 'fermentable', where 'non-' meant 'not' and 'fermentable' meant 'capable of undergoing fermentation.'

'fermentable' comes from the noun/verb 'ferment' (from Old French 'ferment' and Medieval Latin 'fermentare'), which in turn derives from Latin 'fermentum'/'fermentare'; the modern English adjective 'fermentable' developed by adding the adjectival suffix '-able' to 'ferment', and 'non-' was later prefixed to form 'nonfermentable'.

Initially, 'ferment' and related forms referred to leavening or the substance causing fermentation; over time the sense broadened to chemical/biological conversion by microbes, and 'fermentable' came to mean 'capable of being fermented', so 'nonfermentable' now means 'not capable of being fermented'.