Why You Should Think Twice About Baking Brownies In A Glass Pan

Much like chocolate chip cookies, the humble brownie can be surprisingly divisive despite its simplicity. Some people covet the crusty corner pieces, while others would rather forgo the dessert altogether than give up a soft and chewy center square. Some like the crunchy bite of nuts in their brownies, while others prefer a homogenous texture. Some like to eat their brownies cold, while others risk minor burns in order to gobble them right out of the oven. And while there's no wrong way to enjoy a brownie, it turns out there might be a wrong dish to bake them in: one made of glass.

Before you go giving away all your Pyrex, know that tempered glass pans are a wonderful vessel for lots of recipes. In fact, when Corning Glass Works patented Pyrex in 1915, it was so popular that it became known as "America's Favorite Dish." Allrecipes confirms that glass pans are great for casseroles, baked meat and pasta dishes, bread puddings, pies, and cobblers. But, according to a PopSugar article by Susannah Chen that cites Lauren Chattman's "The Baking Answer Book," brownies will reach their most evenly cooked potential in an aluminum or nonstick dish. Here's why. 

Gooey in all the wrong places

Drawing from Lauren Chattman's book, Susannah Chen at Popsugar explains that "clear glass, much like dark metal, absorbs heat, making it ideal for crisp-crusted pies but much less so for brownies, bar cookies, and fruit crisps, which can easily become burnt." The outlet also adds that ceramic pans, though more ideal than glass, tend to yield "a lighter-colored product."

Allrecipes backs up this theory: "Glass bakeware is heavier and slower to heat than metal, but once it's hot...it retains that heat for much longer. So when using a glass pan to bake something like a cake or batch of brownies, you may find that the sides and bottom are brown at a much faster rate than the interior cooks."

That said, if all your non-glass pans are dirty and you need to bake some brownies stat (we highly suggest adding mascarpone to the batter this time), Chen says they'll turn out fine as long as you reduce your oven temperature by 25 degrees below what your recipe recommends.