You can start/make your own kombucha tea by making sweet tea with about 2 tablespoons of apple cider vinegar.
I use 5 little bags of Liptons Brisk Tea, 2 cups of brown sugar, 2 tablespoons of pure maple syrup to make a gallon of tea.
Brew the tea and add to a wide mouth gallon jar that has the sugar and syrup in the bottom so that they will dissolve when the warm tea and water is added up to just below the bottom of the neck.
Add the organic apple cider vinegar and mix with a wooden spoon.
Cover with cheesecloth/tee towel and set in a corner out of direct sunlight and check on it in about 8 days depending on how warm it has been. 6-7 days if it's been real warm. No more than 10 if it's been in a cool climate.
After these days, depending on where you are, it starts to get stronger.
Do not store in the refrigerator in plastic containers as it will start to "leech" the chemical from the plastic.
I make sure that my hands are very clean and use Pyrex bowls to place the mushroom in while I strain the tea into another gallon jar, leaving about a 1/4 cup of tea in the bottom for the catalyst of the next batch that I have ready to go before I pull the mushroom.
I pour it in, mix it, and place the mushroom on top of the next batch with the light side up and dark side down.
Repeat process and pull mushroom in 7 days. HTH.