Kombucha is a fermented tea drink that has bacteria and yeast some people say have health benefits.
The Starbucks version is made with Evolution Fresh's cold-pressed juices, which are added to an artisinal-tea base of Congou black tea, yerba mate, pu'erh black tea, green tea or matcha.
The six Evolution Fresh Organic Kombucha flavors are Ginger Lemon Honeycrisp, Mango Pineapple, Ginger Greens, Spicy Greens, Pink Grapefruit and Turmeric Pineapple Coconut.
Starbucks bought the juice company in 2011.
"We know our consumers are looking for beverages with functional benefits and Evolution Fresh Organic Kombucha is just what they are asking for — a delicious and refreshing pick-me-up that also supports digestive wellness," Evolution Fresh president Ryan Ziegelmann said in a statement.
The kombucha and fermented beverage category grew 36 percent in 2017, Starbucks said, citing data from the Chicago-based market research firm IRI.
The drinks, which come in 15.2-ounce bottles, are certified USDA Organic, non-GMO, gluten-free and kosher, according to Starbucks.
This isn't the coffee chain's only recent zig away from its core product. The company opened its first standalone Princi bakery and cafe last month in Seattle; Starbucks first invested in Princi in 2016. And in June, the company launched a line of Teavana packaged teas in grocery stores, seven months after doubling-down on that brand by selling its Tazo tea brand to Unilever for $384 million.
A bottle's suggested retail price is $3.99. The fat-free kombucha has between 40 and 45 calories and 3 to 7 grams of sugar, depending on the flavor.