Drinking a glass of kombucha takes raw food to new heights: Sure, sushi might not be cooked, but kombucha is still living.

Companies that sell kombucha promise that thier drinks will promote healthy digestion, regulate metabolism, and improve the immune system — thus helping to fight off winter colds. Often (mistakenly) called “mushroom tea,” the drink is made by adding tea and sweeteners to a solid mass of live cultures. It is left to sit for seven to 30 days, producing a sweet and tangy drink, with a slight fermented fizz.

Homemade kombucha in black tea and mint tea flavors, is sold for $4 at Brooklyn’s Marlow and Sons restaurant (81 Broadway at Wythe Avenue, 718-384-1441). And Millennium Products’s two kombucha drinks — GT’s Organic Raw Kombucha in flavors such as gingerade and citrus, and Synergy, containing 95% kombucha liquid and 5% fruit juice — are available at natural and organic markets across the city. Bottles are $3.19 at Whole Foods Markets (95E. Houston St. at the Bowery, among other locations, 212-420-1320).

“It’s one of the few raw bottled beverages out there.” the founder of Millennium, G.T. Dave, said, touting the virtues of his brand during a phone interview yesterday. “Foods that are not processed or minimally processed are better for everyone.”