Not sure where tepache fits in to these forums but I'll try here...
I made a batch of tepache, and after fermenting it for a few days, I strained it and put it into an air-locked 1L jar, bottled one bottle and left it to ferment a few days before putting it in the fridge. (The bottle I took out of the fridge was not at all carbonated even though it was still sweet, the air-locked jar is still bubbling. )
At the time of the first bottling I decided to reuse the pineapple by re-topping it with the leftover tepache from the first batch, and some more sugar water. At first it did nothing, then it started bubbling, so after a couple days I bottled it to try to carbonate it.
It was left in a warm spot over night, and the next morning there was this super thick, spongy solid mass floating on the top (looks like a jelly-fish and it is not foam) and there are lots of bubbles but I opened one up and it was only lightly carbonated.
I have made tepache and carbonated it before and it turned out perfectly (tasted a lot like apple cider)... but now I can't seem to recreate it.
Not sure what this is growing on top or how it could have formed so quickly, should I toss this or just strain it before drinking?