This is my first cider. I threw in some grapes I'd frozen a while ago. I bottled directly from primary. 2 weeks in the bottle and I checked on it, saw the sludge on the left. A night in the fridge and then poured off the clear cider into one glass and the sludge into another. So much sludge. A good 15-20% of the volume. Lesson learned - rack to 2ndary for clarity sake.
I don't think its the end of the world. Can still taste good even with bits of yeast in there. I'm not an expert but might also be the kind of yeast you put in there. Yeast with lower alcohol tolerance will die off sooner and won't be able to keep going after racking it. Also could cold crash your brew right after bottling and that'll keep the yeast from going crazy.
Hmm. I don't think it was the yeast. Could be, but I don't have this much stuff when I use it in beer. shrug it was safale us05.