After I allowed the polish to rise for approx. 10 hours ( it had risen quite a bit) and I placed in the fridge overnight - I find that the level has dropped from the high it had prior to refrigerating ? Why ?
Yeast fermentation slows down under refrigeration but does not stop altogether. After 10 hours, the poolish probably exhausted all of its food for the yeast. Putting it in the fridge did not accomplish much of anything afterwards. It needed to be fed again.