It may sound weird, but I cannot tell if my F1 is sweet, sour, or tart. It tastes like all of them. I have 3 different batches going, one with green + black tea, another with green + white tea, and another with green + hibiscus, they all taste differently, but they also all taste slightly sour, weirdly sweet, and have a vinegary after taste. This has happened in the past also with other batches I have done, so I don't think it's because of the tea I used. How can I tell if it's done?