“The atoms in there are stressed and they’re trying to pull themselves apart,” explained Jane Cook, PhD, the former chief scientist at the Corning Museum of Glass.
As the inside cools, it pulls at the stiff, compressed outer layer, which puts the center of the glass in tension. During that heat-tempering process, the exterior of the glass is force-cooled so that it solidifies quickly, leaving the center to cool more slowly. Tempered glass is soda-lime glass that has been heat-treated for durability.
This shock causes different parts of the glass to expand at different rates and often crack from stress, making soda-lime glass a poor candidate for bakeware.Īn untempered soda-lime glass shattered after tumbling off a 3-foot-high counter onto a marble slab. It’s also more susceptible to breaking from thermal shock (sudden or extreme changes in temperature, such as what happens when you pour a hot liquid into a cold glass). Untreated soda-lime glass is far more likely than the others to break from a tumble off your table. It’s the most common-used for everything from drinking glasses to pickle jars-because it’s versatile and inexpensive to produce. Let’s start with the basic soda-lime glass. And for each, you have three things to consider: Will it break easily if dropped? Will it break if heated or cooled? What does it look like when it breaks? Three basic types of glassware are typically found in most home kitchens: soda-lime, tempered, and borosilicate.
When tempered glass-which is what most glass Pyrex bakeware is made of-breaks unexpectedly, it can be pretty shocking and potentially dangerous (not to mention frustrating when it ruins your Thanksgiving pie). These tales crop up regularly in Amazon reviews and news reports, such as this 2010 investigation by Consumer Reports. It shows a sheet cake baked in metal at 350 degrees, in glass at 350 degrees and in glass at 325 degrees.You may have heard dramatic stories about Pyrex bakeware “exploding” or shattering seemingly out of nowhere. Once hot, it's able to maintain a steady temperature, which is a good thing for baked goods. You're right: Pyrex, and other tempered glass, takes longer to heat up and longer to cool down than metal. Pyrex® glassware and lids are dishwasher safe, making cleanup easy and carefree. Pyrex® lids cannot be placed in conventional or convection ovens (because they'll melt), unless specifically noted on the package that they are designed for oven use (as with Pyrex® Ultimate Storage silicone and glass lids). What temperature is Pyrex safe in oven? Pyrex® glass is good for normal use temperature of 446 ☏ and maximum use temperature 914 ☏.Īlso know, can I put a Pyrex lid in the oven? The tempered glass lid allows you to check the recipe without disturbing the cooking progress or temperature. In this way, can you put glass lids in the oven? Can be used in a preheated oven, microwave oven, refrigerator or freezer. Can be used as a cover for your Pyrex glassware in a preheated oven.
Glass lids: The warnings provided above for your Pyrex glassware also apply to glass lids. Pyrex glassware is dishwasher safe, and may also be washed by hand.