You can make your own kombucha at home using water, white granulated sugar, blacktea, and looseleaf.

No it is not

Consumption of kombucha tea has been observed to cause stomach upset, yeast infections , allergic reactions, nausea , and headache . Persons with stomach ulcers may find that kombucha increases their symptoms.

Technically, you do need a bit of SCOBY, but you only need a very small amount. Many commerical 12oz bottled Kombucha teas have enough SCOBY to start a new batch. The Symbiotic Culture Of Bacteria and Yeast is Acetobacter (acetic acid bacteria) and yeasts living together. Vinegar is made with a different type of SCOBY called "Mother of Vinegar" and Kefir is made with another type of SCOBY called "kefir grain." You can buy the Kombucha scobies / cultures online here: http://www.crazyfortea.com/kombuchaculture.html Organic and 100% guaranteed. Comes with instructions.

Kombucha is a fermented tea drink made from sweetened tea and a culture of bacteria and yeast. It is believed to have originated in Northeast China around 220 BC and has gained popularity for its supposed health benefits.