Alfred co-founder Gemma Pears said the agency would launch a series of campaigns and implement a new social media strategy designed to reposition SodaStream as a health and sustainability brand aimed at young families.
The agency will also help raise awareness of Israeli firm SodaStream's commitment to reducing plastic waste by building on the sustainability message that was central to an April Fools' Day stunt featuring socialite Paris Hilton, Pears told PRWeek.
She said: "SodaStream’s commitment to raising awareness of the plastic waste crisis, as well as its health and wellbeing approach, provides us with a solid platform to tell many compelling stories."
The six-figure brief also includes an influencer relations strategy - although Pears said this was unlikely to include further work with Hilton.
Alfred, which Pears set up alongside Dan Neale in 2013, takes over from Engine-owned PR firm Mischief, which held the account for two years. The agency declined to re-pitch for the business.
Mischief CEO Frankie Cory told PRWeek that because of the agency's recent business wins – including Asda – there had been "a few changes" across the business, with SodaStream being one of them.
"We remain on great terms with the client team there, and we may well work with them again in the future," Cory said.