Glass vs. Metal: Are You Baking With the Right Pan?

Considering my job as a food writer, my kitchen is very poorly stocked when it comes to bakeware. I have limited storage space in my New York City apartment, plus I tend to concentrate on savory cooking. So when I do want to bake, I often don't have the right equipment (e.g. I tend to skip any recipe that requires a stand mixer).

If, like me, you have a baking equipment setup that's a bit minimalist (doesn't "minimalist" sound better than "lacking"?), you might be wondering if you can get by with just metal or just glass bakeware. How much does the baking material matter and is it OK to ignore the instructions in the recipe and just grab whatever cake pan, muffin tin, cookie sheet, or other piece of baking equipment you have on hand?

To find out, I turned to Jürgen David, Director of Pastry Research & Development at the Institute of Culinary Education’s New York City campus. The TLDR answer is that metal beats out glass in most cases, but there are a few exceptions. Read on to learn about the pros and cons of baking with metal vs. glass, plus when it's OK to substitute one for the other. 

The Pros and Cons of Metal Baking Pans

Pros of Metal: "Professional chefs don’t bake in glass dishes," David says bluntly, so clearly he's on Team Metal. The main advantage of baking with metal is how quickly and well it conducts heat, which helps baked goods cook evenly and brown nicely.

David points out that dark metal conducts heat even better than light metal, so if you're looking for extra speed and browning, seek out dark metal pans. "Think of wearing a white t-shirt versus a black one in the sun and how the black one feels hotter," says David. Metal can also stand up to high heat without the risk of breaking like glass can.

In terms of visual appeal, if you like your blondies and brownies with extra-straight edges, you'll also want to reach for metal over glass (that's not top of my personal baking worry list, but I know you perfectionists care). Metal also tends to be cheaper than glass as well, which is a very big selling point. 

Cons of Metal: One of the few disadvantages David notes about metal bakeware is that if it's particularly thin it can warp. It can also be damaged by abrasive cleaners.

You can help protect your metal pans by letting them cool completely before putting them in water for washing since the shock of a quick temperature change can cause them to warp. And stick to nonabrasive cleaners. If you follow these two rules, your metal bakeware should last for decades. 

The Pros and Cons of Glass Baking Pans

Pros of Glass: David has a strong preference for metal for most baking applications, however, he says that while glass (along with porcelain and ceramic) conducts heat slowly it holds heat very well—unlike metal, which heats quickly and cools quickly. This ability to hold heat makes it work well for certain recipes in which you want to have even heat for a long time but don't need browning, such as lasagna, baked custards, and both savory and sweet casseroles (like bread pudding or french toast casserole). Glass's ability to retain heat also makes it great for keeping desserts warm once they're out of the oven. 

Glass can also be good for fruit-based recipes like crumble or crisp since the acids in some fruits like citrus and berries can react with metals like aluminum and produce an unpleasant metallic flavor.

Glass is also good for desserts like Rice Krispies treats that aren't actually baked since it's naturally more nonstick than metal.

Some cooks also like the fact that glass is transparent, which can come in handy when you're making things like pie crust so you can see if the crust still looks raw or is burning. It also shows off any dessert with pretty layers. 

Cons of Glass: We've already covered that glass conducts heat slowly, which is why you will want to avoid cooking anything that you want to brown well in glass, as well as anything with a short cooking time, like biscuits and cookies. Baking in glass can also lead to uneven cooking—things like brownies can get overly browned, dried out, or burnt on the sides and edges before the inside cooks through.

The biggest con of baking with glass is that it can shatter when exposed to high heat or heat fluctuations. If you are baking with glass, look for a heat-safe-to temperature on the dish and never heat it to a higher temperature than that. Also never put a glass pan into the oven straight from the freezer or the fridge, and always let your glass pans cool to room temperature on a cooling rack (not directly on the counter) before putting them in water. 

When It’s OK To Substitute Glass for Metal and Vice Versa

If your recipe calls for a certain baking material, your best bet is to stick to what it calls for, since the recipe was presumably developed and tested with that material in mind. Most recipes will call for a tin for metal and a dish for glass or ceramic, while a pan can refer to either.

In a pinch, you can swap one for the other in many recipes. Just keep a close eye on whatever you are baking since the food may brown or cook more quickly or slowly than expected.

As a rule of thumb when substituting glass in a recipe that calls for metal, chef David suggests lowering the temperature by up to 25°F and extending the baking time by five to 15 minutes, and you'll need to keep a close eye on whatever you're baking. 

If a recipe calls for glass and contains very acidic ingredients, steer clear of baking in aluminum or cast iron (stainless steel is OK). If it calls for metal, never use glass at a higher temperature than the manufacturer advises, and never put it under the broiler.

The Takeaway

"I find most glass or ceramic dishes to be visually appealing and they let you see the food as it’s cooking, but using metal pans browns the food faster and is not a concern in terms of breakage," says David. So, listen to the pro, and if you are only going to keep one sort of bakeware around, opt for metal over glass.

In most cases, metal will bake more evenly and brown and crisp your baked goods better. If you do substitute glass for metal when baking, be aware of temperature limits and never expose the glass bakeware to abrupt temperature changes—so for all you neatniks, no doing the dishes the moment you serve that berry cobbler!