Add the juice of 1 orange, the cardamom pods into a clean bottle.
Place the funnel and sieve (if using) on top of the bottle. Gently pour in the plain kombucha, leaving a couple of inches of air space at the top. Close the bottle.
Let it sit at room temperature for 2-3 days. This is the second ferment.
Burp the bottle every day or so to release any carbonation build up.
After 2-3 days, when the desired fizziness and flavour is reached, place the kombucha in the refrigerator.
Enjoy!
Notes
If you are new to kombucha, start with ¼ cup a day.