James Fayal founded his line of energy teas while working as an analyst at a venture firm in 2014. After a $10,000 crowdfunding campaign, Zest Tea started selling hot teas containing about three times the caffeine levels of traditional teas (on par with coffee and energy drinks). Last year, Fayal launched a line of low-calorie and sugar-free ready-to-drink iced teas, which are sold in more than 2,500 stores across the U.S., including Whole Foods, Safeway, Giant and Shaws.

See Fayal's profile and read the 30 Under 30 story from Forbes.