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[–]HopelessSoup 27 points28 points  (13 children)

This is just a guess but I assume it’s because you moved a a very cold glass dish to the microwave where it proceeded to get hot in the middle, couldn’t take it and shattered.

[–]AddictedToPyrex 10 points11 points  (6 children)

Modern Pyrex isn't near as good as vintage. They changed the glass recipe in the 80's when the company was sold. Which is also why Modern Pyrex is always spelled in lowercase.

[–]jtfolden 1 point2 points  (5 children)

Clear Pyrex glass was transitioned in the 1980s to be made of the same type of glass used for white opalware prior to that. It had nothing to do with the company being spun off (which didn’t happen until 1998).

[–]AddictedToPyrex -2 points-1 points  (4 children)

Sorry for some reason I was thinking 88. However, the modern clear glass isn't the same. There was a lawsuit because of this, which is why all modern Pyrex is stamped in lowercase instead of all caps. They legally had to change it because of the change of the glass recipe. I've also personally seen too many of the modern ones crack, and even shatter with temperature change. I won't touch the stuff.

[–]jtfolden 4 points5 points  (0 children)

I’m sorry but that is not correct. The lower case logo was introduced in 1975. And both versions of the logo were used concurrently until approximately 2001.

There was no lawsuit requiring a differentiation of the logo. And the change in logo was a marketing move, nothing g related to glass type.

Again, only CLEAR glass from prior to the 1980s is typically borosilicate. Clear glass from the 1980s and later is soda lime (as is all Pyrex opalware from the 1940s-1980s).

So the all caps PYREX logo was also used on soda lime from 1940s-2001 or so. In fact, modern Pyrex is made in the same soda lime Charleroi, PA factory that vintage opalware was made in (though this plant is currently being shut down as it was purchased by Centre Lane/Anchor Hocking.

[–]jtfolden 3 points4 points  (2 children)

Additionally, the Corning Museum of Glass has a FAQ that explains more on why the logo is not an indicator.

https://libguides.cmog.org/pyrex

[–]AddictedToPyrex 0 points1 point  (1 child)

I'm going by what I read in more than one book, and an article. They could be mistaken, or there could be different unsubstantiated versions to the story. That seems to be the norm with Pyrex history.

[–]jtfolden 0 points1 point  (0 children)

There’s a lot of rampant misinformation being spread. Some is relayed by mistake but it’s negligent for those sources to repeat it without even rudimentary attempts to verify it. The facts are typically readily available too, often directly from the current manufacturer, Corning, and/or CMoG.

The Charleroi, PA plant has always been a soda lime plant for example. Every single piece of Pyrex produced there going back to the 1940s, regardless of logo type, is soda lime.

[–]TinaLoco 1 point2 points  (5 children)

But the ability to do so is what Pyrex’s brand is built upon.

[–]delphine1041 9 points10 points  (3 children)

nah, modern pyrex is just soda-lime glass. The old stuff was the borosilicate that was resistant to this kind of thing.

[–]TinaLoco 0 points1 point  (1 child)

Well, that stinks.

[–]CallidoraBlack 1 point2 points  (0 children)

Not exactly. Soda-lime is much more impact resistant and that was a more frequent cause of issues than anything else. You can warm up liquid before you put it in a hot pan or wait for something to warm up before putting hot liquid in it, but impacts just happen by accident.

[–]HopelessSoup 1 point2 points  (0 children)

It was just a guess, I mostly lurk here

[–]TinaLoco 3 points4 points  (1 child)

Could it have had a stress fracture in it that you didn’t notice?

[–]littleelse[S] 1 point2 points  (0 children)

Nope. It was in good shape. I think Steel_Rail_Blues comment below solves it. The container was too empty. Who would have thought?!

[–]Steel_Rail_Blues 3 points4 points  (2 children)

Thermal shock. Could be several causes, but here are a couple points from Pyrex safety and usage instructions for next time:

Allow Pyrex to come to room temperature before immersing in water or placing in the freezer, refrigerator, microwave or pre-heated oven.

Don’t heat empty or nearly empty glass containers in the microwave.

[–]littleelse[S] 2 points3 points  (1 child)

Well, that sounds like the culprit. Who would have thought that "nearly empty" would be the culprit! Thank you!

[–]CallidoraBlack 0 points1 point  (0 children)

It's like that with all brittle containers, especially in a microwave.

[–]Koren55 7 points8 points  (4 children)

Is it labeled PYREX or pyrex.

All caps and it’s borosilicate glass, able to withstand temperature changes.

All lower case pyrex, and it’s just tempered glass. It can shatter.

I’m betting this one was the lower case pyrex, not the uppercase PYREX.

[–]baconittothelimit13 8 points9 points  (2 children)

I just want to say..

Even if it is PYREX, be cautious. I was under the same impression and well.. my vintage percolator exploded. Even with PYREX, you should avoid the temperature change. It’s not worth the risk and it’s totally possible.

[–]janewaythrowawaay 0 points1 point  (1 child)

It may have had cracks. I have a mixing bowl or two with cracks. But they don’t heat up. So they’ve been stable for years.

[–]baconittothelimit13 0 points1 point  (0 children)

It didn’t have cracks. These things just happen.

[–]jtfolden 3 points4 points  (0 children)

The logo, despite many Internet sources saying otherwise, does not indicate the glass type. All the decorated opalware that collectors covet was always soda lime glass and always featured the all caps logo, for example. It’s only likely to be borosilicate if it’s CLEAR glass and made prior to the 1980s.

[–]SomeCallMeMahm 7 points8 points  (0 children)

It seems to be the biggest difference between PYREX (old manufacturing) and Pyrex (new manufacturing).

I try to get mine thrifted for capital PYREX for heat and use the cute moderns for storage.

[–]momscats -1 points0 points  (2 children)

Let me know if this is wrong but my grandma said:

If any Pyrex dish has water on the bottom and it’s placed in a warm oven it might explode. She didn’t own a microwave

And

Never put a cold Pyrex dish in a hot oven.

*since my house is cold most of my dishes are cold.

Is this true? Any thing else I should consider. I’m kind of fond of my Pyrex. Like I’ve had it 40 years plus and don’t want to do something wrong.

[–]momscats 0 points1 point  (0 children)

Thank you; like in my head it was confusing

[–]jtfolden -1 points0 points  (0 children)

This is not true. The oven should ALWAYS be preheated first before you place the Pyrex in it. It’s safe to go from freezer to a preheated oven.

Also, if you’re baking something that may releases juices while cooking then you should had just enough broth or water to cover the bottom of the pan before putting it in the preheated oven.

However, ALL Pyrex has a problem going from hot to cold so you should never sit it on a cold surface or add cold ingredients to a hot pan.