Why is my brew not bubbly?

[meneergio]

I bought a Kefirko kombucha fermenter, and am brewing my second batch now, with a mother scoby I've got from a friend.

Both my first and second batch have no bubbles at all. My brew does grow baby scoby's, and I can see a lot of yeast strings and flocks, but it produces no bubbles at all. Not even after bottling and letting it sit for days at room temperature. I followed the brewing instructions in the booklet that came with the fermenter.

Here you see the yeast in my brew.
New item by Giovanni Windey

I also tried second fermentation in a flip-top bottle (I added some priming sugar), and also got zero bubbles. I stirred the F1 brew before bottling, so there definitely is yeast in F2 in the bottle (you can see it in the image below).
New item by Giovanni Windey

So, why is my brew not bubbly, and can I do something to help it carbonate?

 

[rushpapers]

At what temp are your doing F2?

 

[hottpeper13]

Both ferments should be ~80*,I keep mine at 78*,and have good carbonation. Also the sugar is for the booch and will mostly be fermented,so don't use less thinking you're making a diet booch.

 

[meneergio]

At what temp are your doing F2?

At about 20°C (68 °F)

 

[hottpeper13]

Too cold , no fizz. The Big Book of Kombucha says 69* is the coldest but I find 78* to be perfect. Don't go over 86* They suggest storing the scoby hotel at 60*,and that works for me.