'unsalted' originates from the prefix 'un-' meaning 'not' and the word 'salted', which comes from the Old English 'sealt', meaning 'salt'.

'sealt' transformed into the Middle English word 'salted', and eventually became the modern English word 'salted'. The prefix 'un-' was added to form 'unsalted'.

Initially, 'unsalted' simply meant 'not salted', and this meaning has remained consistent in modern usage.