Kombucha is a beverage that can heal you from the inside out. While it is being marketed as something that has been invented this millenia, it has actually been around for thousands of years. Kombucha consists of black tea boiled with sugar, that has then cooled down and in that you place a scoby along with some starter fluid (previously brewed kombucha). You need about one DL of starter fluid for every liter of kombucha you make. After you put everything together in a big jar, you put a piece of breathable cloth on top, tie a thread or a rubber band around, and keep it in a cool and dark place for about 13 days.
Keep checking it to make sure that the scoby that forms on the top of the fluid, is healthy and hasn't got any mold on it. The kombucha should smell slightly vinegar-y. When the 13 days have passed, you'll see that the colour has changed since you started. To know it is finished, take a clean spoon, lightly push down the scoby, and fill it with some of the fluid. Taste it and then you'll know whether you're good to go or if it needs a day or two more.
The scoby is highly nutritious and when you have a lot of them, you can use them to make fruit leather, nutritious candy, stir fry, bandaids and even vegan leather. There are a ton of uses for the scobies, apart from making huge batches of kombucha, or kombucha vinegar.
When your kombucha is finished, you take out the scoby/ies with clean hands and then you pour the kombucha either into some jars or bottles. Keep some of the fluid as starter fluid for the next batch though. Otherwise you won't be able to make a new batch of kombucha.
You can now put your fruits, berries and herbs into the kombucha to flavour it. It will take two or three days for the flavour to truly attach itself to the kombucha. You can then bottle the kombucha and store them either in a refrigerator or in a cabinet, for up to a year. Maybe more, though if you've done it right, I can assure you that they won't be standing in your cabinet or refrigerator for a year. It'll take some serious restriction to not drink it all the first week or month, depending on how much you made. Personally I've never been able to make them last longer than that. It is a beverage that is way too tasty and healthy to stay away from.
Adding a combination of fruits, herbs and berries make for the best flavours, I've noticed. However, if you make a ginger one, you'll end up with an antibiotic beverage that is an even healthier version of ginger beer. You will not be able to keep your hands off of it.
By making it yourself, you will not only improve your health but you'll spend less money on kombucha, ginger beer, soda (if you're into that) and alcohol, because kombucha replaces it all. You will also produce less waste, as all you need is tea and a jar. No plastic required.