Some Questions About Pyrex and Corningware

[boilsover]

1 minute ago, JoNorvelleWalker said:

 

However Visions is not -- never to be confused with -- Pyroceram.  Please.

 

 

Umm...unless you know more than the manufacturer does...  "Why is Visions so light and clear and yet able to handle such extreme changes in temperature? Because it’s made of a revolutionary glass ceramic material called Pyroceram "  See, http://www.worldkitchen.com/en/blog/blog-Visions-the-visions-story.html

[Lisa Shock]

4 hours ago, lindag said:

I have a set of the blue cornflower Pyrex made for microwave use that I got for my first microwave in the mid 70s

I'm still using it and have only had to find a new lid for the little skillet (that I found on eBay).

I've actually I've used it on the stovetop but only under very low heat.  

 

 

 

I believe you are referring to CorningWare, not Pyrex. Pyrex is clear, CorningWare is white and often has patterns on it like the blue cornflower.

[JoNorvelleWalker]

45 minutes ago, boilsover said:

 

Umm...unless you know more than the manufacturer does...  "Why is Visions so light and clear and yet able to handle such extreme changes in temperature? Because it’s made of a revolutionary glass ceramic material called Pyroceram "  See, http://www.worldkitchen.com/en/blog/blog-Visions-the-visions-story.html

 

And they call soda-lime glass Pyrex.

 

[lindag]

8 hours ago, Lisa Shock said:

 

I believe you are referring to CorningWare, not Pyrex. Pyrex is clear, CorningWare is white and often has patterns on it like the blue cornflower.

Ah yes, you are correct....duh.

[boilsover]

8 hours ago, JoNorvelleWalker said:

 

And they call soda-lime glass Pyrex.

 

 

The full story of what is/has been called Pyrex is long and boring.  Suffice it to say, at least in USA, Pyrex could always have been either soda lime or borosilicate--the US plants made both, although now all Pyrex under the World Kitchen license is soda lime.  So if you're buying new in USA, it's soda lime, and it's still Pyrex.  If you're buying vintage, you need some expertise to tell which it is.  If you want borosilicate, you can buy the European manufacture.  In both cases, it's a safety hazard, but soda lime more so.

Edited August 8, 2017 by boilsover (log)

[Porthos]

@boilsover I am having trouble finding any information about pre-1998 Pyrex that used soda lime glass. Do you have any links handy for me to peruse?

[boilsover]

6 hours ago, Porthos said:

@boilsover I am having trouble finding any information about pre-1998 Pyrex that used soda lime glass. Do you have any links handy for me to peruse?

 

Handy?  No.  But I believe it was discussed at length here:  https://www.chowhound.com/post/consumer-reports-investigates-exploding-pyrex-751340

 

Corning had two plants, the epoymous one at Corning, and the other at Charleroi, PA.  While the latter has been making Pyrex since the 1930s, the Corning plant is no longer in operation.  It's my understanding that the Charleroi plant made both soda lime and borosilicate until the early 1990s, and which time it dropped borosilicate manufacture.  This predates World Kitchens license of Pyrex from Corning in 1998. IIRC.

 

Here's a source, quoting Corning and WK people, that Charleroi has been making soda lime Pyrex for 60 years:  http://www.snopes.com/food/warnings/pyrex.asp#BDYHoeyAKzyLdaaE.99

Edited August 9, 2017 by boilsover (log)

[Porthos]

@boilsover Thank you.

[lindag]

Reading though this thread made me think back to the set of Pyrex bowls in Mom's kitchen in the 50s.

Her signature dessert was made-from-scratch banana pudding put together in that big 'ol yellow bowl!

 

Edited August 25, 2017 by lindag (log)

[Toliver]

1 hour ago, lindag said:

Reading though this thread made me think back to the set of Pyrex bowls in Mom's kitchen in the 50s.

Her signature dessert was made-from-scratch banana pudding put together in that big 'ol yellow bowl!

 

 

My mom has (or had, I should say) the same set of bowls. All that remains from over the years of use are the red bowl and the small blue bowl. They epitomize the nostalgia of days- gone-by for me so I bought a set on eBay a few years ago. Thanks for the trip down Memory Lane! 

[chromedome]

My mom still has all four, as well. I've just helped her move, so I can vouch for that personally.

 

She also still has several pieces of the Tupperware I remember from the 1970s, and even one or two that used to be my grandmother's. Goodness knows how old those are. 

[Porthos]

On 8/25/2017 at 6:59 AM, lindag said:

Reading though this thread made me think back to the set of Pyrex bowls in Mom's kitchen in the 50s.

Her signature dessert was made-from-scratch banana pudding put together in that big 'ol yellow bowl!

 

 

 

My dear MIL, who passed away 15 years ago, had this set in slightly different colors with a wheat motif. They are still in my FIL's kitchen.

Edited August 26, 2017 by Porthos (log)

[gfweb]

Nice piece on the exploding pyrex issue

https://gizmodo.com/the-pyrex-glass-controversy-that-just-wont-die-1833040962

[rotuts]

Compensation for senior executives of most if not all major companies has been tied to the companies stock price for some time now.

 

the notion that ' business success ' for a company can be best measured by its stock price came out of the Harvard Business School at some point

 

therefor it is in the financial interest  of the companies executives to cell a cheaper ( possibly inferior )  product tied to a well known brand, for profitability.

 

I cannot recall the book that discussed the shift at the HBS that started this trend.  anyone know about it ?

 

it might be this one :

 

https://www.amazon.com/Golden-Passport-Harvard-Business-Capitalism/dp/0062347179

 

Ill get it from the library and see

Edited March 23, 2019 by rotuts (log)

[rotuts]

I did get this book , and read about the last 1/3d

 

no Coq au Vin Rx's that I could find

 

but  I cannot recommend this book

 

unless you are familiar with the Options Desk

 

and have some ' Calls ' on your mind related to PeptoBismol 

 

pass this book around ( well written it is ) to your many friends

 

ad you might do well

 

still , no notable Rx's in the book.

 

BTW  OnTopic :

 

pleased for all the original iPot Crew 'cash-ing out '

 

glad I have a few iPot's on the Reserve List

 

purchased at Rock Bottom Prices.

Edited March 23, 2019 by rotuts (log)

[weedy]

so...

tonight I placed a Pyrex 10" pie plate under the broiler to char some tomatillos and onions (something I've done 100 times before)

 

then I pulled it out and went to tip it over into the blender jar, and the plate literally exploded into shards in my hand.

It never touched anything, over than perhaps the lip of the polycarbonate blender jar (which was far from 'cold'), when it just burst

 

anyone else seen this?

 

I know they don't make Pyrex like they used to (sad to say) but this seemed uncalled for.

 

I wasn't planning on my salsa being quite this crunchy.

 

 

Edited May 14, 2019 by Smithy
Adjusted title (log)

[kayb]

I've had one explode in the oven, but that was my fault for putting a cold dish in a hot oven.

 

Helluva mess, too.

 

[AlaMoi]

under the broiler will do it just about every time.  the glass rim probably got a lot hotter than the stuff in the pie plate, pouring the 'cold' juice out shocked the hot rim more than it could take.

 

"Here are just SOME of the Pyrex® Safety and Usage Instructions:

• “NEVER use the product on top of a stove, under a broiler, in a toaster oven or place over oven vent or pilot light.”

 

 

Edited May 14, 2019 by AlaMoi
oops! (log)

[robirdstx]

I am surprised it took this long to fail!

[weedy]

5 hours ago, AlaMoi said:

under the broiler will do it just about every time.  the glass rim probably got a lot hotter than the stuff in the pie plate, pouring the 'cold' juice out shocked the hot rim more than it could take.

 

"Here are just SOME of the Pyrex® Safety and Usage Instructions:

• “NEVER use the product on top of a stove, under a broiler, in a toaster oven or place over oven vent or pilot light.”

 

 

 

300 degree 'juice' cracked the (maybe) 450 degree rim???

seriously?

Edited May 14, 2019 by weedy (log)

[palo]

I would suspect the rim was much hotter than 450 degrees.

 

p

[AlaMoi]

yes, seriously.  borosilicate glass aka Pyrex will withstand about a 340 degree F temperature 'shock' before the thermal stress exceeds the mechanical strength.  the new stuff from tempered soda lime glass is not as resistant to thermal shock.

anything liquid in the pan is not over 212'F plus a bit for 'contaminants'

the max temp differential applies to "perfect" condition - any nicks, chips, etc cause stress risers and it'll shatter 'quicker'

normal wear and tear on 'the good old stuff' most likely has resulted in those kinds of nicks - even microscopic chips count when dealing with stresses in glass....

 

there are lots of reports exceeded only by the hysteria on the topic - but my all time favorite is the often cited Consumer Reports research which, in the best imitation possible of Myth Busters . . . could not cause it to shatter so they ignored all the rules and managed to shatter one.  if it didn't break, use more C4.....

[palo]

Anyone had this issue with Corelle dishes?

 

p

[andiesenji]

Corning Pyroceram was made to use in the broiler, rangetop, oven and fridge to oven. Freezer to oven is okay to a cold oven.

Pyrex - even the "Flameware" is NOT FOR USE UNDER A BROILER!  

Cold Pyrex from the fridge is  problematic into a hot oven.  Room temp Pyrex marked BAKEWARE is okay room temp to hot oven UNLESS THERE ARE SCRATCHES ON THE GLASS.  Which is one reason not to use a sharp knife when cutting a pie or anything in a Pyrex loaf or cake pan.

[paulraphael]

Some info here.

 

Does anyone still make things out of borosilicate glass?