How Pyrex Transformed Every Kitchen Into a Home-Ec Lab

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Sadly, it’s now tempered soda lime glass…


That was an absolutely lovely read.


Pyrex glass cookware manufactured by World Kitchen is made of tempered soda-lime glass instead of borosilicate.[12] World Kitchen justified this change by stating that soda-lime glass was cheaper to produce, is the most common form of glass used in bakeware in the US, and that it also had higher mechanical strength than borosilicate—making it more resistant to breakage when dropped, which it believed to be the most common cause of breakage in glass bakeware. Unlike borosilicate, it is not as heat-resistant, leading to the potential increase in breakage from heat stress. European Pyrex is still made from borosillicate

You’d think that this is what trademark law was supposed to resolve, but alas, no.

And in some states, cooking with good glassware is illegal.


…and that’s why we can’t have nice things.


European Pyrex, made by Arc International, is still borosilicate. Good luck finding any at a reasonable price. You can get Arcuisine and Simax on Amazon. There’s also Marinex, made in Brazil. Each of these is also a borosilicate formulatiion.


Fortunately, flea markets nationwide nearly always have the original borosilicate Pyrex on sale by someone. I have found the original colored Pyrex mixing bowls, to match the ones my mother used nearly every day as we kids were growing up in the 40s and 50s, She also had a double boiler she used for sauces and desserts–I think one of my sisters has that. Nearly all the original Cornflower Blue Corningware is now long gone.


I do not know how to tell the difference. If I use a soda-lime pie plate for years, thinking it is borosilicate, will I be in for a rude awakening… I dunno, maybe if I go on a TV show about glass?

Don’t leave the pie plate over an open flame?

I think he means a pie diesh that he bakes in (because it is weird to call something non-metal a “pie pan”). Also, stress from heating includes stress from cooling. A relative of ours first found out, “they changed the formula for Pyrex (decades earlier),” when her pie dish exploded while cooling on the stove.

Have you ever boiled water over a bunsen burner in a glass flask? It’s amazing stuff, this PYREX®, isn’t it.

What if I told you you could get the same heat proof glass for your kitchen? Now you can. All the benefits of glass, without the sensitivity to temperature changes. Buy PYREX® now!

Oh wait. They changed the formula? Never mind.

I suppose that if you’ve never worked in a lab, and never cooked prior to whenever PYREX became soda lime glass. you won’t know the difference, and PYREX is just another brand of fragile kitchen glassware.

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This changing composition into inferior formula while keeping the brand name should be punishable by death by a shooting squad at dawn. I don’t insist at the dawn part.

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It happens all the time when a manufacturer gets eviscerated for parts, licensing out the brand name to unrelated inferiors: Bell & Howell, Black & Decker, Zenith, Schwinn. But Pyrex wasn’t just the brand name, it was the name of the material itself! It’s like if they started making Krazy Glue out of mucilage instead of cyanoacrylate.


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