Pitch or Keep? White Floaties in

I'm looking for some advice from you experienced folks: do I dump these cider bottles now down the drain or later into a glass?

I'm pretty new to this cider making adventure, but this particular batch has been an adventure. Basic ingredients was UV-pasturized fresh cider, Nottingham - primary from 1055 to 998 - racked to secondary, added 100% black cherry juice (in a bold/foolish attempt to make cherry cider) and was in secondary for 5 weeks. Ever since the first sample in secondary it has been very very sour in taste. So, to combat that, I primed with apple concentrate and bottled a week ago. I was planning on pasteurizing on the stovetop today, but ame to find these white islands floating on the surface of about half the bottles.
Cracked one today to check the carb level, and it's pretty good. Sour taste is still there alright.
The white breaks up and falls to the bottom if you disturb the bottle much.
Thanks for your thoughts.

 

I get that in my ciders too from time to time its either yeast or pectin. I give my bottles a gentle spin every now and again to settle that and yeast stuck on to the bottle walls

 

Phew! I really like that answer. Thanks.