65-year-old Smith died on March 23 at his home in Lake Oswego, Oregon, US media reports said.
The cause was complications of liver cancer, said his daughter, Carrie Smith-Prei.
His enchantment with tea and wizardry at blending flavours had helped turn the United States into a nation of tea connoisseurs, the reports said.
Dubbed the "All-Star Alchemist of Top-Shelf Tea" by the Wall Street Journal, Smith helped put Portland on the map as the capital of gourmet tea as co-founder of the Stash and Tazo brands, which became multimillion-dollar success stories with their emphasis on premium ingredients and whimsical aura.
More From This Section
"Steve Smith was among those who bear much credit for today's tea renaissance in the US," said tea historian James Norwood Pratt, noting that the United States not only imports and consumes four times as much tea today than it did 20 years ago, but it also surpasses both Britain and Japan in tea consumption.
"He had a masterful palate. And he was a genius of a blender."
"He made being productive very fun," said Tony Tellin, formerly Tazo's chief taster and now director of operations at Steven Smith Teamaker, the last company Smith founded.
Traveling around the world to source his teas, Smith also was devoted to improving the lives of tea workers by sponsoring humanitarian projects in Darjeeling and Assam through the Portland-based Mercy Corps.
After Starbucks bought Tazo in 1999 for USD 9 million, Smith continued to guide the brand's marketing and development.
In 2006 Smith retired from Starbucks and moved to the south of France. Then, in 2009, he launched Steven Smith Teamaker in an old Portland blacksmith shop with his wife, Kim DeMent, to make small-batch, artisanal teas.