Fermentation is all about transformation.
First you start with your brew and create an environment conducive to the growth of bacteria and yeasts. They break down while they digest sugars, converting them into acids and bacteria that are good for us.
It is the sugars from the added flavourings that create the fizz in the bottles.
1) Pour your kombucha into a bottle using a funnel, leaving only 2cm-4cm of space at the top.
2) If you are using a 1lt glass bottle, fill it with 900ml of your brew then add 1/3 cup of your favorite fruits, veggies, juices and herbs to each bottle.
Generally 1 part flavouring to 9 parts kombucha.
3) Seal the bottles and store in a warm, dark place for 2-3 days. Release the gases daily or your could have an explosion.
4) After 2-3 days, strain out the fruit and move your bottles to the refrigerator.
5) Once chilled, pop the top and enjoy your very own home-brewed kombucha!
Stir your first brew before you pour it in to the second ferment bottle, the yeast will help with the fizz.
Also choose a proper fermenting bottle, the cheap bottles with a flip top lid that are meant for water have thin glass, and can explode under pressure.
If you use natural juices to flavour, you will not need to strain anything out and this will help keep the carbonation.