Making kombucha is really easy, and you can make it from scratch for a very low cost.
What you need:
A bottle of store-bought kombucha (one with "the mother", go for a not-too-flavoured one)
2 glass jars with a large opening
Mesh (or other light fabric)
Large bottles (thick and solid enough for carbonation)
Flavourings (fruit juices, fruit, dried fruit, rose water, fresh mint, etc.)
How to do it:
1. Get a bottle of kombucha. I currently live in Montreal, so I got a bottle of RISE Kombucha, ginger flavoured. I can't vouch for other brands.
2. Pour the content of the bottle in a glass jar. Cover the top of the jar with mesh held by a rubber band.
3. Leave on your counter top until a 1/4-inch thick mother kombucha has formed on top of the liquid (about 2 weeks).
4. Bring to a rolling boil a large amount of water for a few minutes (this takes away the chlorine from the water).
5. Put 2 1/2 tsp of black tea, a little less than 1/2 cup of organic sugar and about 5 cups of the boiled water in a pot/ jar/ whatever doesn't melt. Let it sit for a while (I just walk away).
6. When the liquid is at room temperature, strain it while pouring it in the other glass jar.
7. Take the kombucha mother with clean hands and gently put it in the tea/sugar mixture. Pour about 1 cup of the already-fermented kombucha in the jar. Cover jar with mesh. Leave jar in a spot away from direct sunlight.
8. After one week, taste the kombucha. If it's still very sweet, leave longer (up to a month).
9. When it's ready, take the kombucha mother out with very clean hands. Put it in a non-plastic, non-metal bowl with about 1 cup of kombucha from the batch you just made (for your next batch).
10. Strain the kombucha into a large thick bottle (or large thick bottles). Fill the bottle(s) about halfway.
11. Add your flavourings. I like to put about 20 to 40 % stuff and 60-80 % kombucha. Sometimes I put more stuff, sometimes less. I love to chop fresh apples and strawberries and just stuff them in the bottles, or to pick fresh mint from my garden and stick it in a bottle with kombucha.
12. Tightly seal the bottle(s) with lid(s). Leave the bottle(s) on your counter top for about 2 days.
13. Open the bottles slowly and carefully (drink will be fizzy). Stop fermentation by putting bottle(s) in the fridge.
14. Strain the content of the bottles. Enjoy (better when cool).
15. For a new batch, start over again from step 4.
Simple rules about kombucha:
1. Never put metal in contact with a fermenting kombucha or a mother kombucha. It harms the culture.
2. Avoid letting your kombucha ferment in a plastic container. Use a glass jar.
3. Cover you kombucha with mesh held by a rubber band. You can't cover a kombucha in its first fermentation because it needs to breathe, but you can't either just leave it open, unless you want a whole colony of fruit flies in your house.
4. In the first fermentation, avoid moving your kombucha jar too much. Taste with a straw or non-metal spoon to figure out if the taste is okay.
5. Keep the kombucha away from direct sunlight.
6. Try to keep the kombucha away from too much heat.
7. Handle the kombucha with very clean hands, and use very clean material in the whole process.
8. Don't let a mother kombucha dry out or swim in a liquid other than kombucha.
9. Measurements are approximative. You can add flavourings to taste.
I found out today that after straining the kombucha at the end (step 14), you can just pour water in the bottle to extract a little more flavour from the flavourings. I did it with my cranberry-apple and my lime-mint kombucha by filling the bottles with water and just forgetting them 3-4 days in the fridge. They turned out into refreshing, light drinks with a hint of kombucha flavour!
To understand more how it actually works, see Cultures for Health; it's really excellent. I just wanted to make a post that showed kombucha as a non-intimidating thing to make.
Il est trop tard pour ça aujourd'hui... :-(