How long do you let your scoby in booch?

[RiverViking]

I acquired a scoby from my sister about five years ago. I properly made booch out of it for about 8 months and let it sit for about a year or so. When I finally checked on it, and tasted the booch, it was super acidic, nearly undrinkable. I threw out the yucky scoby layers and started my brew back up. I've four-one gallon everbrew batches going now from that original batch.