'fermentation-preventing' is a modern English compound formed from 'fermentation' + the present participle 'preventing' (from 'prevent'). 'Fermentation' ultimately comes from Latin 'fermentum'/'fermentare'. 'Prevent' comes from Latin 'praevenire' via Old French 'prevenir'.

'Fermentation' entered English via Latin and Old French (e.g. Latin 'fermentum', Medieval Latin 'fermentatio', Old French forms) and became Middle English 'fermentacioun'/'fermentaciōn' before the modern English 'fermentation'. 'Prevent' came into English from Old French 'prevenir', itself from Latin 'praevenire' ('prae-' + 'venire'), passing through Middle English as 'prevenen' or 'preventen'. These elements were combined in modern English to form the compound adjective 'fermentation-preventing'.

'Fermentation' originally referred to 'leaven' or 'bubbling' (the action of fermentation); 'prevent' originally meant 'to come before' (in the sense of anticipating or stopping). Over time the combined compound has come to mean 'stopping or inhibiting the process of fermentation'.