ALL NATURAL : KOMBUCHA'S U.S. STORMINGS

THE RECENT U.S. kombucha craze has been fermenting for decades.

All-natural, low-sugar, and packed with supposed health benefits, the once-niche drink has invaded grocery stores, supermarkets and cafes.

U.S. sales of the cloudy bubbly beverage reached $412 million in 2018 according to Nielsen data up 42 percent from the year before.

The now-ubiquitous fermented drink, whose exact origins are unknown, is even stocked by the  American retail giant Walmart. Across the United States, it's not uncommon to find shops offerings up to 10 different brands.

For Alex Ingalls, who founded Pilot Komboucha in 2015, the buzzing popularity of the slightly alcoholic drink [the kind sold in stores only has 0.5 percent alcohol content] is due to ''a mix of things.''

A ''hardcore base'' that has drunk Kombucha for years, was likely drawn to its supposed health benefits, particularly for the digestive system, she said, though there has been no clinical study on the matter.

The claim is based on the fermentation process used to make Kombucha, which contains probiotics; live micro-organisms that can help the growth of  intestinal bacteria.

However, Ingalls mainly sees the Kombucha wave as the result of its major advantage over sodas and even juice : low sugar levels.

''These days, everyone is very conscience about sugar intake,'' she said.

''They're trying to drink less soda and even less diet soda,'' whose ingredients have raised eyebrows over the years.''

''Since I don't drink so much soda, when I settle on something flavor. I think Kombucha is a pretty good alternative,'' said Renata Ontman, after a class on Kombucha-making at the Brooklyn Brainery recreation center.

The course was taught by Cheryl Paswater, founder of the Kombucha company : Contraband Ferments.

''I always try to eat as healthy as I can, and I think [of it] as a sort of snack in the afternoon,'' said Sarah Gilberg, who also attended the class, adding that the fizzy beverage makes her feel energized. [Agencies]