Does it make any difference whether I use a glass or metal baking dish?
Absolutely, says Hugh Rushing, executive vice president of the Cookware Manufacturers Association. His organization represents 22 manufacturers who together are responsible for about 95 percent of the cookware sold in the United States and Canada, and has done extensive testing of their products.
Glass is an insulator, which means it takes longer to heat up, but once it does, it stays at a stable temperature, even in an oven that’s constantly turning on and off. To compensate for those long heating times, you might have to extend cooking times for 5 or 10 minutes. Glass pans also cook more evenly than metal ones, which often get hot spots.
Rushing says glass is best for foods like cakes, which bake for a relatively long time at lower temperatures. As in a thick cast iron pan, cornbread baked in glass will brown more evenly than if you use a thin metal dish. However, glass bakeware cannot be made in large sizes and is generally unavailable with a nonstick coating—Teflon is very hard to apply to glass. Other disadvantages of glass are that it is more expensive and much heavier than metal, and it can shatter if its temperature changes too quickly.
Metal pans heat up and cool down quickly, which means they are good for items baked at high temperatures for short times, like biscuits. The type of metal pan you use can also make a difference. Metal with a dull finish absorbs heat faster than shiny metal, so that cookies baked on a dull cookie sheet might get too dark on the bottom before they are cooked on top.