Though most folks are discerning when it comes to picking a recipe, sometimes it’s hard to know what the best tool for the job is. This is especially common when it comes to baking, and while the age of the yeast or the quality of cocoa powder matters, so too does the baking dish. And one common area of confusion is whether to use metal or glass.
The science of baking involves complex chemical reactions that occur when you place batter or dough in the hot environment of an oven. This is why the material of the bakeware is important and can change the outcome considerably. Here, we break down the pros and cons of using metal and glass.
First, Let’s Talk About Conductivity
Metal and glass have different heat conductivity, which means they carry and transfer heat differently. According to A.J. Bates, professor of chemistry at Skyline College in California, metal heats up quickly, conducting heat to whatever you’re baking quickly (metal also cools down faster). He explained that glass, on the other hand, has a higher specific heat capacity, which means it takes more energy and time to heat up and retains the heat after it’s been removed from the oven.
Baking in metal means you can bake a dessert until the center is done, remove it from the oven, and not have to worry about the pan continuing to bake the edges. Glass, however, will retain the heat, and continue to bake what’s inside, resulting in either an underbaked center or an overbaked edge—or often both.
Glass and Metal React to Ingredients Differently
Metal and glass also react to ingredients differently. Acidic ingredients like tomatoes and citrus can react with aluminum (the most common metal used in bakeware), creating a metallic taste in your food. This is why lasagna and other casseroles with acidic ingredients are often baked in glass. The smooth slick surface of the glass is also naturally somewhat nonstick, making it easier to clean baked-on cheese and other crusty ingredients.
Consider Practical Use and Storage
Metal is quite durable and can take a beating in a busy kitchen, while glass is fragile and heavy, requiring a little more care in cleaning and storage. Some glass can also suffer thermal shock, which means it can’t handle extreme temperature changes. For example, if you move a glass dish from the freezer to the oven, or from a hot oven to a cold stove, the glass can shatter. The exception to this is borosilicate glass, which is more thermal-shock resistant than other types of glass (which is why it’s often used to make microwave cookware, like this set from Anyday). However, keep in mind that most common glass bakeware is not borosilicate. Metal doesn’t have this issue, allowing you to chill a pie crust in the freezer before moving it directly to the oven to bake.
Glass can also be difficult to store since pans are often inconsistently sized, as well as heavy and thick. If you have pets or inquisitive young kids, or just don’t have a lot of storage space, opt for metal bakeware.
Attractiveness Matters
Baked goods served directly from the dish can benefit from a handsome glass or ceramic dish. Alanna Taylor-Tobin, author of Alternative Baker and blogger at The Bojon Gourmet recommends baking cobblers, crisps, and crumbles in glass or ceramic. “I love using attractive ceramic and glass baking dishes for fruit desserts. The dish retains heat, keeping the dessert warm, and it looks nice too! So desserts like my almond flour apple crisp can go from the oven directly to the table for an easy yet dinner-party-worthy dessert,” she says.
However, if your dessert is removed from the dish before serving, like with brownies, cookies, or bars, a metal option is going to give you a more attractive final product because the edges and corners of a metal dish are often an ideal 90-degree angle, creating a perfect square or rectangle.
So, Which Bakes Best? Glass or Metal? The Answer: It Depends on What You’re Baking
Most desserts like brownies, cookies, bars, and cakes bake best in a metal dish. The metal conducts heat evenly and efficiently, allowing the baked goods to heat and rise equally from edge to center, cooking at the same rate.
Desserts like fruit cobblers, crisps, and crumbles, as well as savory casseroles, are best made in a glass dish. The glass retains the heat better, keeping the dish warm, and the dish can go directly from the oven to the table.
One thing to note about pies and tarts: a lot of recipes and articles will tell you to bake pies in glass, and it’s true that glass has the added advantage of being transparent—you can easily see if the pie crust is done. But, if you’re an experienced baker or want your pie to have an extra flaky crust, metal is a superior option. Pie crust is flaky because there are shards of butter in between the layers of dough. When heated, the butter melts, and the water in the butter creates steam, which gives the crust its layers and flakiness. Glass does heat up faster than fancy stoneware pie pans, but metal heats up even quicker, creating an evenly browned crust with loads of flakiness. And, with metal, you can place the pie crust in the freezer to chill the dough thoroughly before moving it to the hot oven, which is riskier with a glass pie dish, since it can shatter.
Do keep in mind that pie bakers are divided about what sort of pie dish they prefer, with a lot of recipes developed with glass pie pans. If you pick metal as your pie pan, your bake time might be less and need to be adjusted.
Tips for Baking in Glass Instead of Metal
If all you have in your household is glassware and you don’t wish to buy any metal pans, you want to adjust the time and temperature of the baking. Kristina Razon, a former Serious Eats editor and avid baker suggests dropping the temperature of the recipe by 25°F and increasing the baking time by five to 10 minutes. Keep in mind that glassware continues to retain the heat longer than metal pans, so you might want to also take the pan out of the oven slightly underdone and let the carryover heat continue to bake the dessert while it sits.
In the End, Use What Works for You
Finally, one last thing to consider: If you have favorite recipes that work with the pans that you own, you don’t need to change what you’re doing! You know your kitchen and your equipment best. Every kitchen is different, and every oven is different. If you have a favorite recipe for brownies that works perfectly with your favorite glass dish, then by all means, keep baking with it. It’s possible you’ve already adjusted your baking time, temperature, and method to accommodate for the glass material, your oven bakes at slightly lower temperatures than most ovens, or you have family members who love the fudgy, slightly undercooked inside pieces and others that fight over the crispy corner pieces.
But if you are trying a new recipe or trying to figure out why your cookie bars are always coming out hard and overdone at the edges and underdone and raw in the middle, try baking a batch using a metal pan instead of the glass one. You might find switching pans is all you need to make the recipe work.
FAQs
Which is better for baking: glass or metal?
For baked desserts like cakes, cookies, and brownies, metal is better. Most recipes are designed and developed for metal pans, and you’ll be able to replicate the recipe in your home if you use a similar pan. For fruit desserts like cobblers, crisps, and crumbles; desserts that have a lot of acidity like citrus; or savory dishes like casseroles, glass is probably better, as it is non-reactive and easier to clean; it also keeps food warmer longer, which is great for serving.
What’s the best way to clean glass and metal baking pans?
The best way to clean a glass pan is to hand wash it with warm soapy water. Soak the pan first if there is baked-on residue; this will soften and loosen the gunk, allowing you to scrub it off more easily with a sponge. Avoid harsh scouring pads, as they can scratch the surface of the glass.
To wash metal baking pans, soak the pan first in soapy hot water if there are crumbs stuck, but usually, a sponge and hot water will remove most of the residue. Your glass or metal baking pan might also be dishwasher safe, but consult the manufacturer's cleaning and care instructions first before putting it in the dishwasher. And realize that some pans may be listed as dishwasher safe, but harsh dishwashing detergents can corrode or shorten the lifespan of the dish.