When to Use Glass Bakeware and When to Use Metal

Baking a lasagna? A pie? A roast? When you are choosing a pan to bake or roast your food, the pan you reach for shouldn’t just be the first one you can grab, regardless of the material, because some materials great for certain situations and terrible for others.

Most of us gravitate towards metal baking sheets when we are baking a batch of cookies, but glass dishes for lasagnas and casseroles. It’s almost instinctive, but there are reasons for choosing a metal pan over glass, or vice versa.

Glass is a poor conductor of heat, but it also distributes heat more evenly. What that means is that glass doesn’t pick up heat quickly, but once a glass pan is hot, it will stay warm much longer outside of the oven. This can be a great feature if you are serving casseroles or braises that you would like to stay warm for as long as possible once out of the oven and set on the table. This goes for ceramic dishes, too.

Glass pans aren’t recommended when you want to broil foods because they may shatter. In fact, glass pans should never be used in direct high-heat cooking situations, like on the stovetop (unless otherwise specified from the manufacturer). So if you are roasting a meat and want to make a pan gravy on the stove after, stick to a metal roasting pan, not a glass pan, or else you will have to transfer everything to a pot first before making your sauce. Personally, I don’t like creating more dirty dishes than I have to when I’m making dinner.

• Glass Bakeware YES: Casseroles and braised dishes that will be served directly to the table.
• Glass Bakeware NO: When broiling or shifting from oven to stovetop.

Metals, especially aluminum, are generally better at conducting heat: they pick up that heat but can lose it again quickly.

Grab metal baking pans when you want foods to heat up quickly and if you want them to brown, like when you are roasting potato wedges.

And because metal baking pans are better heat conductors, they will also cool more quickly once retrieved from the oven. If you are investing in aluminum baking sheets, opt for a thicker grade of aluminum so they can also serve for baking cookies without causing them to burn too quickly.

Avoid using metal bakeware, especially iron and aluminum pans, with reactive foods (foods that are acidic or basic), because these foods will react with the metal, discoloring the pan, leaving a grayish tinge on the layer of food in contact with the surface of the pan, and often adding an unwanted metallic flavor to those foods. Examples of things not to bake in aluminum or cast iron pans are fruit crumbles and savory cobblers. I learned this lesson the hard way when I discovered my strawberry-rhubarb crumble literally cleaned the surface of an old baking tin (presumably aluminum) from my grandmother but also made the fruit taste metallic and look grayish. The luscious fruit at the bottom was rendered unappetizing and basically inedible.

• Metal Bakeware YES: Quick-roasting foods and when you want browning
• Metal Bakeware NO: Reactive foods such as fruit; foods that you want to keep warm for a period of time before serving.

Some baking sheets are actually two layers of metal with a layer of air in between. Air conducts heat poorly and therefore acts as an insulator to significantly slow down the transfer of heat and help even out the heat on the surface of the sheet. Insulated baking sheets are a great weapon in the battle against burned cookies.

Is this pretty much how you decide which material to use when reaching for a baking pan? Or do you have other tips and criteria that help you choose between glass and metal?