Exploding (actually exploded) Pyrex.
The other day I pulled a carton of eggs out of my poorly designed and overstuffed top-freezer fridge. It snagged a 1L Pyrex measuring bowl filled with congealed stock. The bowl tumbled onto the floor, a distance of 34 inches, and shattered into dozens of sharp edged fragments. Not what I expected from a glass container I count on to hold up to tough treatment. We are not talking about extreme temperature changes which are sometimes cited as a Pyrex hazard; the chilled container and contents had zero time to adjust to the ambient kitchen temp.
According to this allrecipes explainer, there are currently two types of Pyrex, neither manufactured by Corning Glass which originated the product. pyrex (lower case) is made of tempered soda-lime glass and is sold in the US, South America and Asia; PYREX (upper case) is made of borosilicate glass and is sold primarily in Europe and the Middle East. Borosilicate is more shatter resistant but is toxic and expensive to dispose of. When I think of tempered glass, I think of the shower of glass pellets you get when some thug breaks your car window; infuriating but unlikely to hurt you. But in my case, the exploding pyrex left jagged shards all over the kitchen floor.
This thread in the r/Baking reddit has multiple tales of exploding lower-case pyrex, including a photo of a bake pan which self destructed on the stove top. Most of these are temperature-differential incidents in which the exploded fragments embedded themselves in walls and cabinets, often with bits of the baked product to leave a sticky mess. So I got off lucky, I guess.
The final word can be found in a very detailed (complete with footnotes) Wirecutter article on nytimes.com, misleadingly titled “Why We’re Not Worried About Pyrex Bakeware ‘Exploding’”. A researcher points out that irregular shapes and thicknesses as well as manufacturing defects can make a tempered glass object more vulnerable to breakage; a measuring cup with its handle certainly has more variation than a baking dish. Another researcher posits that a tempered glass item might not break if you drop it on the floor but could have invisible damage that causes it to self destruct in the future. Bwahaha….
Wirecutter touts a few premium baking products that are made with borosilicate, including PYREX (uppercase) from France. But they don’t deliver to the United States, alas. Amazon tells me I ordered a 3-piece nesting set including the exploding 1L twice… once in 2014 and again in 2017. The website currently shows lower case pyrex products but the remaining two in my possession are PYREX. I was managing a rental property at that time and it’s possible I left a set there and needed a replacement. In any case the product switch appears to have happened in that 3 year interval and I guess I am lucky to have kept 2 out of 3.
Who else has a tale of exploding pyrex? (or PYREX?)
