Coke has to work hard to justify a shift from sugary drinks .

Coca-Cola is paying a highly caffeinated price for a global coffee hit. The American soda giant has joined the battle to satisfy consumers’ thirst for java by paying $5.1 billion for Costa, the world’s second-largest chain of cafes. The deal requires Coke to order up new markets for hot drinks.

Investors in seller Whitbread are the big winners.

The deal is the third big coffee transaction so far this year. In May, JAB Holding Company, owner of Krispy Kreme doughnuts, paid $2 billion for Britain’s Pret A Manger, weeks after Nestle shelled out $7.2 billion for the right to sell Starbucks-branded products.

Consumer giants are eager for a fix of a business that Euromonitor forecasts will grow at a steady 3% annually over the next four years.

Coke’s existing coffee business, which includes the Georgia brand in Japan, is small, and running Costa’s nearly-4,000 cafes will be a departure.

Acquiring what the U.S. company calls a scalable coffee platform presumably means it will develop Costa-branded drinks which it can push through supermarkets and vending machines.

Expanding network

It could also expand the chain’s network of self-service machines, though the Atlanta-based company has less experience of pouring out hot beverages.

Delivering a decent return for the $190 billion company’s shareholders will, therefore, be a grind. In the year to March 1, Costa generated an operating profit of £123 million on revenue of about £1.3 billion. To generate an acceptable after-tax return on its investment of close to 8% by 2020, Coke would need to boost Costa’s revenue growth to 20% a year from 8% in the last two years and double its operating margin, Breakingviews calculations show.

The real boost goes to activist investors Elliott Advisors and Sachem Head, which had pressured Whitbread boss Alison Brittain into spinning off the coffee business. Coke is paying 16.4 times Costa’s historical EBITDA, above the 15 times valuation investors award to larger rival Starbucks.

Shareholders will get most of the cash, while Whitbread will invest some of what is left in its chain of Premier Inn hotels. Coke will have to work hard to justify a shift away from sugary drinks. Whitbread shareholders, meanwhile, can enjoy their caffeine boost.

(The author, Carol Ryan, is a Reuters Breakingviews columnist. The opinions expressed are her own)