Borosilicate is a premium type of glass, so durable that it is trusted for use in scientific laboratory equipment. This unique type of glass has specific properties making it desirable for use in bakeware.
What are the Best Borosilicate Glass Bakeware Pans?
- OXO Good Grips 3 Qt Glass Baking DishI– love this model for its sleek design and ergonomic handles.
- Simax Exclusive Clear Rectangular Glass Roaster–This model comes with a tight-fitting plastic lid to make storage a breeze!
- Volarium Glass Baking Dish for Oven–This casserole dish doubles as a beautiful serving tray with tasteful detail.
These three glass baking pans are excellent choices for a wide variety of uses from casseroles to brownies. But what exactly is borosilicate anyway, and what makes it so great compared to other types of glass bakeware?
OXO Good Grips Freezer-to-Oven Safe 3 Qt Glass Baking Dish
- Ideal for lasagna, mac and cheese, dinner rolls and more
- Strong, borosilicate glass construction for freezer to oven use Withstands extreme temperature changes without the risk of cracking or shattering
- Glass won’t stain or absorb odors and is easy to clean
- Generous handles provide a safe and secure grip
- Convenient dimension markings ensure you’re baking with the right size
What are the Advantages of Borosilicate Glass Bakeware?
The biggest advantage of borosilicate glass is that it’s shatter-resistant when compared to other common types of manufactured glass. Unlike most other types of glass, borosilicate can endure extreme changes in temperature—so much so that you can even put a frozen casserole straight into the oven without the need to slowly bring it to room temperature first. Doing this with a non-borosilicate glass baking pan would very likely result in the pan exploding.
Regular glass is prone to shattering because it’s a poor conductor of heat. Glass is a great insulator, meaning that it will maintain its temperature for a long time but is slow to change temperature. This makes glass disposed to what is known as thermal shock—when the temperature change causes different parts of the pan to expand or contract at different rates which in turn can cause the pan to crack or shatter. Borosilicate glass, made from silica and boron trioxide, is rather impervious to this type of thermal shock. For more information on the heating properties of glass, this Recipe Recon article is a great reference.
Because of these unique properties, another advantage of borosilicate glass is that it can withstand higher temperatures. While most tempered glass pans do not recommend going much beyond 400 degrees for concerns over shattering, borosilicate glass pans can safely be heated up to 500 degrees.
It’s also known for its durability. Regular glass is prone to scratching or cracking which can eventually form larger cracks damaging the pan and potentially injuring the user, while borosilicate is largely resistant to this type of damage. Because of its scratch resistant surface, borosilicate glass bakeware also makes for great serving ware that will continue to look great on a table setting even after years of use.
Does Anchor Hocking Use Borosilicate Glass?
Anchor Hocking is top name when it comes to glass bakeware. So why doesn’t it appear on this list? Anchor Hocking stopped using borosilicate glass about forty years ago—the company claims that its motivations for the change were primarily safety and durability as well as consideration of environmental impact.
Although borosilicate is extremely durable, tempered soda-lime-silicate glass may actually be more durable than borosilicate when it comes to dropping. Since dropping is reported as being the most common reason for breakage and injury resulting from glass bakeware breakage, that is a huge consideration.
Additionally, studies have shown that soda lime glass is safer when it comes to actually breaking. Since there is no way to guarantee glass won’t shatter, instead of trying to prevent it, they looked into the way that it shatters, and the subsequent hazard created from the break. When borosilicate breaks, it breaks into thousands of tiny, sharp pieces while soda lime glass is engineered to break into larger, duller pieces to limit the chances of injury.
Although Anchor Hocking made the change earlier, other U.S. based brands that were using borosilicate glass also had to change their processes to comply with air pollution regulations in the 1980s. Borosilicate, when compared to other types of glass, requires more heat and therefore more energy to produce.
Virtually all brands in the U.S. today are using a type of tempered soda lime glass—the same type of glass as Anchor Hocking. That is why my top three choices for borosilicate glass pans are all manufactured overseas.
What is the Difference Between Glass and Borosilicate Glass?
While they all may look very similar to the naked eye, there are actually several different types of glass. Soda lime glass is the oldest and most common type of glass, making up about 90% of the world’s glass.
Tempering is a process that makes glass stronger, safer, and more heat-resistant. Most of the glass used in today’s bakeware as well as windows, glass bottles, and many other commonly used glass products are made from tempered soda lime glass.
Borosilicate glass was engineered in the late 1800s for use in chemistry labs with the goal of being even more heat-resistant than tempered soda lime glass. Borosilicate was widely used in bakeware in the early 1900s, but because of safety and cost considerations, most glass bakeware today is made of tempered soda lime glass.
Both types of glass bakeware are microwave-safe and are safer when compared to metal pans when it comes to not leaching chemicals into your food and not reacting with acidic ingredients. With a clean look, glass bakeware offers versatility since it can easily be used for a serving dish as well as a baking vessel. For more information and recommendations on metal and glass bakeware, check out this Recipe Recon article.
Check Out Our Other Articles on Recipe Recon:
- Crepe Pan vs. Crepe Maker: Which One Is Right For You?
- How to Thicken Banana Pudding for the Perfect Consistency
- 75 Essential Kitchen Items for Home Chefs: Make Restaurant Quality Meals at Home
- The 3 Best Borosilicate Glass Bakeware Pans: Are They Shatterproof?
- The 3 Best Coolers for Sous Vide: Insulation is Key
Why did Pyrex Stop Using Borosilicate Glass?
Pyrex, like Anchor Hocking, used to use borosilicate glass but switched to tempered soda lime glass in the 1980s to comply with new pollution regulations. In addition to its production having a lesser environmental impact, it also happens to be less expensive. Because borosilicate requires more heat and energy to manufacture, it’s more expensive to make than tempered soda lime glass. This was likely another motivating factor for companies like Pyrex to make the switch.
It is rumored that Pyrex switched from borosilicate because it has toxic properties, but that is not the case. Both borosilicate and soda lime glass manufactured today are free of lead and BPA. Glass in general is much safer than plastic and metal in that it is non-reactive and non-porous. However, it’s important to beware of “vintage” glass bakeware produced in the mid 1900s by Pyrex or other glass brands. The opaque painted glass vessels manufactured during this time very likely contained lead which could potentially leach into your food, so it’s best to avoid baking in them.
How Can You Tell if Glass is Borosilicate?
You probably cannot tell if glass s borosilicate just by looking at it. When purchasing glassware, be sure to check the accompanying literature to find out what type of glass your pan is made of. If you have an old glass pan, you can tell if glass is borosilicate by placing it in a liquid of around the same refractive index, which is 1.474 in the case of borosilicate. Mineral oil is a common household substance with a similar refractive index; if the glass is indeed borosilicate it would seem to disappear in the mineral oil.