Traditionally, free kombucha starter cultures are passed from friend to friend, according to The Kombucha Journal. Proponents of the slightly effervescent kombucha beverage refer to the culture as a baby mushroom. Akin to mother of vinegar, kombucha culture is fungal in nature, but not a true mushroom.
Every new batch of kombucha tea starts with flat, gelatinous mass called a SCOBY, or symbiotic colony of bacteria and yeast. When placed in sweetened brewed tea, the culture ferments, producing a beverage that kombucha proponents tout as beneficial to health.
If no friend offers free cultures, one may purchase kombucha starter kits at CulturesForHealth.com, Williams-Sonoma.com and Amazon.com.