I have been working on a brownie recipe and changed the recipe by substituting 70% chocolate for baking chocolate, and reducing the amount of sugar to compensate for the 30% of the chocolate that is sugar. The brownies behave completely differently, with a drier crumb and a faster rise, resulting in a crisp firm top layer that produces an air pocket when the rest of the brownie falls after removing from oven. The baking chocolate brownies have a denser crumb and are much easier to remove from the pan (we are using jumbo muffin tins). Both are made with chocolate produced by a small batch artisanal chocolatier.
Any thoughts as to what is going on? We are using untempered 100% chocolate in the baking chocolate version and tempered 70% chocolate made with organic sugar. Is something happening with the cocoa butter?