While it's true that borosilicate glass is more resistant to thermal shock, it's not immune to it. Also, if you are clumsy like me and frequently drop things or stack them carelessly during storage, the glass may get microcracks that you can't see.
This being said, you do need to follow one major rule when using Pyrex: Avoid extreme temperature changes. Shifts from one extreme to the other can cause thermal shock to the dish which can cause it to crack or shatter entirely.
However, if the dish is heated too quickly or is subjected to a sudden change in temperature, it may shatter. This is because tempered glass is more brittle than regular glass and can break easily if it is stressed.
Next-Level Heat-Proof
This silica stands up well to extreme temperatures, ranging from -40° to 300°C. It also has a low level of thermal expansion, so PYREX glassware doesn't significantly expand or contract when you heat or cool it. As a result, PYREX lab glass has a very low risk of breakage.
Yes. Both the old and newer soda lime versions of Pyrex can break when dropped. However, the soda lime glass is said by the manufacturer to be less likely to break when dropped. Still, the old borosilicate glass is so very much stronger to rapid changes in temperature, so I always choose that instead.
During testing, soda lime glass shattered at lower temperatures than “more expensive” borosilicate Pyrex® bakeware, the report continued. It turns out that the iconic glass bakeware produced in America today is of soda lime, while the European-made products Consumer Reports tested were borosilicate.
It is stronger than regular glass but it can still break or crack if it is dropped or hit hard. It is important to handle borosilicate glass with proper care to minimize the risk of breakage.
Pyrex, made of borosilicate glass, has a low coefficient of thermal expansion. This means it doesn't change size drastically with temperature shifts, preventing cracks when moved from hot to cold environments or vice versa.
Pyrex eventually switched to tempered glass most likely because boron is toxic and expensive to dispose of. Although tempered glass can better withstand thermal shock than regular soda-lime glass can, it's not as resilient as borosilicate. This is what causes the shattering reaction people are talking about.
The effects of thermal shock are great and can cause the glass to break. Even pyrex (like Pyrex) can break when improperly poured boiling water. To prevent the glass from breaking when exposed to boiling water, sudden and drastic temperature changes should be avoided.
It's what made Pyrex famous. The glass part can withstand up to 752°F with a sudden temperature difference no greater than 248°F, per Pyrex's specifications for their standard borosilicate glass.
Baking glassware such as Pyrex dishes in usable condition should be donated to local thrift stores or otherwise reused. If unusable they should be thrown away in the trash. They should not be added to curbside recycling. They are made of a different material than glass bottles and jars.
The maker of Pyrex glassware and Instant Pot multicookers has filed for bankruptcy protection, with as much as $1bn (£790m) in liabilities. Instant Brands blames high interest rates and weak demand for its problems. The company, which has more than 2,400 workers, plans to keep operating while it shakes up the business.
Pyrex products were made of borosilicate glass until the 1950s. At that point, they switched to manufacturing products with tempered soda lime instead. Today, every piece of bakeware made in the U.S. uses tempered soda lime, including the full line of Pyrex consumer glassware.
Brittle materials like glass are much more vulnerable to thermal shock, because they break when their molecules quickly expand under heat or contract under cold.
Because borosilicate is the most durable when it comes to withstanding temperature changes, it is generally considered the safest choice for glass bakeware.
I contacted Pyrex to ask if there's an easy way to tell what material your Pyrex dish is made from, and the company had a simple answer: Look at the logo. If it's all caps “PYREX,” it's vintage, made of borosilicate. If it's lower case “pyrex,” it's new, and it's soda lime.
Pyrex is oven-safe up to 425 degrees. However, direct contact with heating elements can cause the glass to shatter or break.
At its core, Pyrex is glassware and cookware that can resist chemicals, electricity, and heat. It is also shock-resistant and can withstand thermal expansion. As a result, it's an appropriate material to make cookware. Pyrex is also well-suited for lab tools, such as beakers, flasks, and test tubes.
According to Pyrex's safety and usage instructions, “While the glass is designed for temperatures typically used in baking, it can break when exposed to the direct heat element while the oven is preheating.”
pyrex: Lowercase indication of containers that should not be heated in the oven or microwave. These are most likely made of soda-lime glass. PYREX: Uppercase label on cookware that is made of borosilicate glass and can be heated in a microwave or oven.
The lawsuit accused Pyrex manufacturer Corelle Brands LLC of switching the type of glass used to make its products. According to the complaint, Pyrex glassware was originally made of borosilicate glass, which is more heat tolerant. However, Corelle allegedly later started using less-expensive soda lime silicate glass.