I have done almost 30 batches I believe, and I let almost all of them go for 14 days in F1 at a temperature of 82. After that I have been bottling them in flip top bottles and leaving them for a few more days, sometimes 3, sometimes 5, sometimes longer since they don't always carbonate (I'm still learning).

One of the reasons I was leaving them longer in F1 was because I was testing them with Ph strips, trying to get it down to 2.5, but I have a suspicion that those Ph strips I had were not all that good since it seems like the colors of them were always the same.

One issue I have been having is that during F2, they don't all carbonate, so I have been adding more sugar. But, since F1 was 14 days, it's very acidic to begin with. The result of this was sweet acidic kombucha that was way too sweet and had quite the kick, like drinking vinegar.

What I did with the latest batch is I just left the F1 for about 7 days and then bottled with fruits for F2 that lasted for 3-5 days. I had my concerns about this because after about 7 days of F1, it was still a bit sweet to me, but I may just be very used to it being acidic after 14 days that it just tastes sweet to me if it's not that acidic as it normally is.

So far, this has worked great! There isn't that strong acidic taste and feeling in the throat as if I am drinking vinegar, and they carbonated even after 3 days. So I would say this is a successful new path I will try for the next batches, and I will also try to leave them longer for F2 since they are a bit sweet for me right now.