You will need a plain brewed batch of kombucha to move onto flavouring with a second ferment.
Turmeric & Mandarin
Mint & Pineapple
Raspberry & Lime
Apple & Rhubarb
Once you've made your green or black tea kombucha batches it gets exciting!
I never used to second ferment, but now I've started I'll never go back!
The options really are endless, so all you need to know is once your plain brew is done, add some flavour combos to your bottles prior to pouring your booch in, put the lid on and leave out for a further 1-4 days. You will get some fizz from this second ferment, that's normal and makes it better I think!
Be careful at this stage to use a flip top lid or very heavy duty glass jars as there can be explosions and they are messy!
When its fizzy enough pop it in the fridge. I take the fruit out by using a plastic strainer and funnel it back into the jar, or you can leave the fruit in there, up to you.
These second ferments can last months in your fridge, I probably wouldn't go past 6 months though.
You may, actually you're LIKELY to find new SCOBY's growing over your fruit or on top of your second brews, that's fine!