Four entrepreneurs who studied business administration at the Korea Advanced Institute of Science and Technology (KAIST) have come into the spotlight as they founded a startup producing a functional beverage, instead of getting high salaries from large firms, the university said Monday.

They are Brewguru CEO Park Sang-jae, Chief Technology Office (CTO) Park Hoon, Director of Strategy Choo Hyun-jin and Director of Customer Experience Kim Hyung-jin.

The CEO and the strategy director earned their masters of business administration (MBA) at KAIST, and the CTO is doing an MBA at the university. The customer experience director was awarded a Ph.D. at the university's school of management engineering.

In December 2017, they established the startup manufacturing and selling kombucha, which is produced by fermenting black or green tea using a symbiotic culture of bacteria and yeast (SCOBY).

The drink, which is thought to have originated from Manchuria in northeastern China, has been known as the favorite beverage of Hyundai founder Chung Ju-yung, former U.S. President Ronald Reagan and Hollywood celebrities including Miranda Kerr, Lady Gaga and Amanda Seyfried. 

The Coca-Cola Company, PepsiCo and Dr Pepper Snapple Group have made investments since 2015 to enter the kombucha market as the size of the market in 2017 reached 1.3 trillion won ($1.1 billion) globally, up 37.4 percent from a year earlier, following the growing interest in healthier products among consumers worldwide.

The chief executive, who served as a co-founder of a beer company after winning several brewing competitions here and outside of Korea, aims to introduce Brewguru's kombucha to consumers in the U.S. and China within the next five years.

He also wants more MBA graduates to start their own businesses.

"In other countries, 30 percent of MBA graduates set up their own companies, but business founders who earned MBAs are rare in Korea," the CEO said, citing the fear of possible failure as a reason for the rarity. 

"Our society will not be able to sustain its development unless the number of startups increases. We hope Brewguru becomes a good example of a startup founded by MBA graduates in Korea."

He donated 100 million won to KAIST in May for students who seek to run their own enterprises.