It is also hunting for a digital agency, as it has plans to include online in its marketing efforts.
Karmarama's appointment comes ahead of Taut's first foray into above-the-line advertising since its debut in 2003. An integrated campaign is also planned, and is likely to take in outdoor, press, digital and events. Cake has been retained to handle PR.
Ben Bilboul, the managing partner at Karmarama, said: "Taut came to us with a great team and a great brief: to produce a high-profile campaign that will get people to change their opinion about the sports drinks category."
The brand calls itself the "clean" sports drink, because it has no artificial colours, flavours or sweeteners. The team behind the drink includes the Olympic gold medal-winning rower Matthew Pinsent and the sprinter Darren Campbell.
Past marketing efforts have included sponsorship of the Rainforest Foundation 10km run in London.
Jacqueline Pyne, the marketing manager for Taut UK, said: "Since we started, we have built a solid foundation as a sports brand, focusing on PR, events and sampling.
"This year, we really wanted to turn the volume up and increase awareness of the brand in the mass market."
Taut is sold in Waitrose, some branches of Tesco and Sainsbury's, gyms and the chain of organic supermarkets Fresh & Wild.