In an open letter to Starbucks employees, Schultz praised the moral integrity of the global coffee shop behemoth, which today employs more than 33,000 people across 77 countries.

“I set out to build a company that my father, a blue-collar worker and World War II veteran, never had a chance to work for,” Schultz wrote.

“Together we’ve done that, and so much more, by balancing profitability and social conscience, compassion and rigor, and love and responsibility.”

During his four decades as CEO and chairman, Schultz oversaw Starbucks’ growth from 11 stores in 1987 to more than 28,000 stores globally today. He is also credited with delivering a 21,000% gain in the value of the company’s stock price since its initial public offering in 1992. Last year the Starbucks generated revenues of $22.4bn.

The company has confirmed that the Board of Directors has appointed the former Chairman and Chief Executive of JC Penney, Myron E. Ullman, as its new Chair of the Board and Mellody Hobson as Vice Chair of the Board effective upon Schultz’s retirement.

Addressing a conference at the Starbucks Support Center in Seattle, Schultz acknowledged the “crucibles” the company had faced under his stewardship, including financial difficulties during the 2008 economic crisis and more recently when the arrest of two black men at Starbucks store in Philadelphia sparked international outrage. The latter incident prompted Schultz to order the unprecedented closure of more than 8,000 US stores in on May 29 to provide employees with racial bias training.

“You can’t serve 100 million people a week and have 28,000 stores in 77 countries (and be perfect) – it’s impossible to be able to be perfect,” he said.

Upon his departure, Schultz will receive the honourary title of Chairman Emeritus and he will still oversee the opening of the Starbucks Reserve Roastery in Milan on September 6 – marking the company’s long-awaited entry into the Italian coffee shop market. He will also open the New York Roastery in late October.

Schultz said he will focus on philanthropic and social agendas in the future although has remained guarded on speculation he will make a foray into US politics with a possible bid for the Democratic presidential nomination in 2020.

“I’ll be thinking about a range of options for myself, from philanthropy to public service, but I’m a long way from knowing what the future holds,” he wrote to employees.