In a nutshell you need:
A stainless steel pot capable of boiling 3 quarts water (so a 4+ quart pot)
A clear glass 'Anchor Hawking' type cannister (it's straight up and down) or a Pyrex, clear glass bowl capable of holding a bit more than the 3 quarts, plus the floating 'SCOBY' Kombucha. You just want a wide opening to allow a good surface to air ratio. (Walmart, Target should sell for cheap)
A clean, white, freshly laundered and dried dish towl or a 'flat fold' baby diaper (birdseye cloth is perfect weave for air exchange but no dust or fruit flies to get in)
Black Tea bags (Ie, Lipton regular brew), or Green Tea bags
Filtered (chlorine free) water
White sugar or Organic filtered cane juice succanant (organic white sugar, basically)
A 'SCOBY' (Symbiotic Colony of Bacteria and Yeasts), also known as a "Kombucha Mushroom" though it is NOT a mushroom or of that family/genus.Making it:
You bring to boil 3 quarts of filtered water in the stainless steel pot, add in 1 1/2 cups white sugar and boil for 5 minutes.
You turn off the heat, and add 5 Black tea bags or 4 green and 1 black tea bag, and let it steep for 10 minutes.
You remove tea bags, and let the tea cool down (I leave a lid on the pot to keep out dust and such, and move it to another cold 'eye' or a trivet.
Clean the glass bowl/cannister with warm soapy water, and rinse well. You want to have a SUPER clean, white dish 'tea towel' to cover the bowl/cannister with during the brew period. You will want some string or a large rubber band to put around the rim to hold the towel on (the Anchor Hawking jar has the perfect 'lip' to hold the rubber band on tightly, btw)
Once the tea has cooled about 2 hours. I pour into the clean glass jar/container. I put the cloth over it, and allow it to cool another hour if it's still really hot. You can kill the SCOBY if you put it into too hot of tea. It needs to be just slightly warmer than room temp, or cooler.
But if you let it cool too long, you are inviting things other than the Scoby to grow in it, until you can get the SCOBY in it and going good.
You will get some 'Kombucha' liquid with your new baby SCOBY, you can pour that into the tea first, to reduce the acidity (a good thing) plus it cools off the tea a bit more. If you are already making Kombucha, then pour about 1-2 cups of your previous brew into the new tea to get things going right off. I stir with a plastic or silicon spoon, and then gently lay the new piece of Scoby in the tea. It might sink a bit, that's ok, it eventully will float on top of the tea. The new 'Scoby' mushroom will grow to fit the lid/opening of your bowl/container. The new one will grow on TOP of the old one, or 'mother'.
You cover with the clean cloth, secure with a rubber band, and let this sit undisturbed in a low light area, that has air circulation for 7-10 days. I would suggest letting it only go 7 days to start. The flavor is still slightly sweet and will taste better to you. You can always go longer, to adjust the flavor to your liking.
On Day 7, boil your tea, and have it cooling before you strain off the freshly brewed Kombucha. You do not want to leave you mother and new baby SCOBY sitting around too long. You can give the little 'baby' piece to a friend or compost it. Once you have a full size mother, you can either keep the mother and give away newly peeled off (seperated) top layer, or keep the baby and give the mother. The older, mothers will eventually develop a dark color, but this is fine. Every few months, you can compost the mother, and start off with a new baby for brewing. You can also split them into two jars/bowls, if you are drinking that much Kombucha...
You can drink a few ounces once or three times or more a day. Basically Kombucha will use up the sugar (that's why white sugar is ok, and the preferred feeding medium, less contaminants or stuff to interfere with it) and most, if not all the caffeine is used up and converted in the brewing process. So unless you are only brewing it for a few days, you should have not health concerns on that level. (See Betsy Pryor's Book, "Kombucha Phenonmenon" for more amazing info)
The Kombucha brew becomes this amazing brew of good healthy acids that help your body to detoxify (esp the liver). If you have a healthy functioning liver, then the rest of your body's aches and ills can usually be dealt with by your other organs. That's the 'secret' and mystery behind Kombucha. Some folks report hair gets dark again (if going gray) and that their weight reduces until they reach a healty 'balance'. Others report ills are 'healed' as they feel better and stronger.
So that's the scoop. I am including a set of brewing instructions with mine, that are basically the above.
Hope that helps you and any others wondering what the heck Kombucha is