Innocent's decision to rebrand Juicy Waters was taken to emphasise the drink's "nothing but fruit" ethos, and follows 2005's packaging redesign, which was also handled by Pearlfisher.
The agency was asked to create a new name for Juicy Waters, and chose This Water because of its flexibility and adaptability for future on-pack phrases.
Pearlfisher said This Water would "communicate with short, sharp phrases describing the various flavours, ethics and benefits of the water".
Richard Reed, co-founder of Innocent, said: "Collaborating with Pearlfisher has been an exciting and rewarding process for us. They've worked really hard with our creative team to come up with our creative team to come up with an innovative new brand that offers real stand out."
This Water will appear in supermarkets and independent retailers in the UK from May 7.