Stewart co-owns The Cultured Cup and was the first Texan to be a Certified Tea Specialist. He serves as a Mentor for STI, a member of STAN, and is a frequent speaker at Crow Museum, Dallas Museum of Art, SMU, Deloitte University, and gave a TEDxSMU tea talk. Since 2005, he has taught sommeliers about tea at TEXSOM. In 2019, The Cultured Cup was named "Best Retail Tea Shop" by World Tea Awards.