Why did my cheese do this?

cooked in a home oven on a baking steel. Preheated at 550° and cooked for about eight minutes.

i've tried broiling it for less time but I've found that the dough isn't as crisp as I want on the bottom.

this is a low moisture mozzarella cheese.

cooked in a home oven on a baking steel. Preheated at 550° and cooked for about eight minutes.

i've tried broiling it for less time but I've found that the dough isn't as crisp as I want on the bottom.

this is a low moisture mozzarella cheese.