Harrison Cowley beat two agencies - incumbent Hammond Communications and Lingo PR - to win the brief.
Hammond - which won the Best Consumer Campaign Award for promotion of Jersey Royals at the PRWeek Awards in 2000 - lost out in the repitch.
HC will run a media campaign aimed at 25 to 35-year-old professionals, but aims to ensure the repositioning does not alienate existing customers - mainly women aged above 40.
Account director Carla Marshall said: 'We'll be going for younger titles such as Cosmopolitan and OK!, rather than just Good Housekeeping and BBC Good Food.'
The HC team reports to Jersey Potato Export Marketing Board CEO Stuart Smith.