What makes pyrex break

A long, long time ago in a country we all know and love was a company named Corning. They made Pryex dishes. The material they used is called borosilicate glass. This stuff is indestructible. But like everything else, the Bottom Liners had a great idea: sell the technology to another company.

The Chinese discovered that using soda lime glass was almost as good as borosilicate glass and a lot cheaper. Today, Wal-Mart is the largest distributor of Pryex products.

Corning not only sold the technology to a company called World Kitchen, they also sold the rights to the original Pyrex logo. The consumer will never know. Now it seems people are getting hurt using soda lime Pyrex. We were lucky because the dish broke while the oven was closed and the damage was limited to the oven cavity. Others have been less fortunate. Some dishes explode when they are lifted from the heating rack in the oven with devastating results.

Some people are heavily scarred. World Kitchen is in denial. They say that the dishes are another brand, not theirs. Contrary to their denials the victims usually have more than one of these dishes and the Pryex logo is clearly visible. If you buy a Pryex dish beware.

The label on the front says oven safe, freezer safe, microwave safe. The instructions on the back tell another story. You cannot move a soda lime Pyrex dish from the freezer to the oven and expect it to survive. The fine print does on and on about what you are not allowed to do with the Pyrex dish.

The fine print has prevented World Kitchen from being sued because they have warned the consumer that their Pyrex dishes are junk from the get go. And they are the same price as the original Corning dishes.

Last updated: January 30, Sharing is Nice Yes, send me a copy of this email. Send We respect your privacy. Thanks for sharing. Oops, we messed up. Try again later. When a Pyrex bowl is heated or cooled rapidly, different parts of the bowl expand or contract by different amounts, causing stress. Pyrex cookware is meant to withstand baking, but it cannot be trusted for use over degrees. This means that for recipes requiring higher temps you should use metal pans.

Pyrex Glassware is dishwasher safe and may be washed by hand using non-abrasive cleansers and plastic or nylon cleaning pads if scouring is necessary. Is Pyrex oven Safe? Thermal shock occurs when you take something from a cold environment to a hot one.

It is acknowledged that Pyrex can explode when this happens. 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. Three basic types of glassware are typically found in most home kitchens: soda-lime, tempered, and borosilicate.

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? Untreated soda-lime glass is far more likely than the others to break from a tumble off your table.

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. Tempered glass is soda-lime glass that has been heat-treated for durability. 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.

As the inside cools, it pulls at the stiff, compressed outer layer, which puts the center of the glass in tension. And borosilicate glass is more expensive to manufacture than tempered or soda-lime glass. So if something, such as a crack or flaw, disrupts the compressed outer layer and reaches the tensile zone, that throws off the balance, and the entire piece crumbles into tiny cube-shaped pieces unlike untreated soda-lime glass, which breaks into shards.

Surface damage can result from any rough treatment of glass, such as repeatedly scratching it, dropping it, or banging it against another item in the dishwasher. This damage can weaken the glass without fully breaking it. If you want to get really nerdy, scientists in fracture mechanics call this kind of damage subcritical crack growth.