American Pyrex Less Resistant to Thermal Shock
December 11, 2010 8:38 AM Subscribe
Flying Shards of Hot Glass. Reports of consumer injuries led Consumer Reports to investigate the safety of glass bakeware. It turns out that US-made Pyrex glass bakeware is no longer as resistant to thermal shock as it used to be, nor as resistant as European-made Pyrex still is.
Pyrex glass bakeware was originally made from borosilicate glass, a material whose resistance to breakage due to changes in temperature was so strong that it was used in railyards for lantern glass. Now, however, Pyrex (and main competitor Anchor Hocking) are made from a less expensive material: soda lime glass that has been strengthened through thermal tempering.
European-made Pyrex is still made from borosilicate glass, which enabled Consumer Reports to test brand-new samples of each type of glass, side-by-side, for resistance to thermal shock. "We baked at least five samples of each brand in a 450-degree oven. All of the U.S. Pyrex and Anchor dishes shattered when placed on the wet countertop. None of the European dishes made of borosilicate broke, except one practice-run Arcuisine Elegance dish that had been through two baking cycles in our lab."
In its defense, Pyrex says that given the number of its products in use, the number of reported injuries is small, and also that soda lime glass is more resistant to impact breakage, which is a more common cause of injuries. (Consumer Reports found the resistance to impact breakage to vary widely among samples, but that some samples of soda lime glass were in fact quite strong in that regard.)
Some advice for safer usage.
Pyrex glass bakeware was originally made from borosilicate glass, a material whose resistance to breakage due to changes in temperature was so strong that it was used in railyards for lantern glass. Now, however, Pyrex (and main competitor Anchor Hocking) are made from a less expensive material: soda lime glass that has been strengthened through thermal tempering.
European-made Pyrex is still made from borosilicate glass, which enabled Consumer Reports to test brand-new samples of each type of glass, side-by-side, for resistance to thermal shock. "We baked at least five samples of each brand in a 450-degree oven. All of the U.S. Pyrex and Anchor dishes shattered when placed on the wet countertop. None of the European dishes made of borosilicate broke, except one practice-run Arcuisine Elegance dish that had been through two baking cycles in our lab."
In its defense, Pyrex says that given the number of its products in use, the number of reported injuries is small, and also that soda lime glass is more resistant to impact breakage, which is a more common cause of injuries. (Consumer Reports found the resistance to impact breakage to vary widely among samples, but that some samples of soda lime glass were in fact quite strong in that regard.)
Some advice for safer usage.
Yeah, I'd heard a while ago that Pyrex was no longer made from actual 'pyrex' (meaning borosilicate glass), which made me less interested in getting more pyrex.
posted by rmd1023 at 8:47 AM on December 11, 2010
posted by rmd1023 at 8:47 AM on December 11, 2010
This is scary. But:
1) They were cooking sand, not food--sand gets much hotter than food.
2) You're not supposed to put pyrex from 450 degree oven on WET countertop. I'm pretty sure they explicit say that on warning labels when you buy Pyrex containers.
posted by reformedjerk at 8:52 AM on December 11, 2010
1) They were cooking sand, not food--sand gets much hotter than food.
2) You're not supposed to put pyrex from 450 degree oven on WET countertop. I'm pretty sure they explicit say that on warning labels when you buy Pyrex containers.
posted by reformedjerk at 8:52 AM on December 11, 2010
I was cooking a dish in my oven, and the directions called for me to bake it for a while and then pour a broth over it once it cools. I take it out of the oven and place it on the stove top, which had electric burner. I hate cooking with electric instead of gas, and one of the reasons is that when you turn on the wrong burner, you don't know it instantly, like you do with gas.
So the hot pyrex dish is now sitting on top of the stove, and I accidentally turn on the burner that's under it, instead of the burner that's under the pot with the soup. Next, I take cold broth and pour it into the very hot pyrex dish, and it doesn't just crack, it doesn't just shatter, it EXPLODES!
Glass goes everywhere. At that moment I got a knock on on my door from a guy I met at a party and found out that he lived two blocks from me, and I'm all like "Oh yeah dude, stop by anytime, I usually work from home, seriously, let's hang, I'm not just saying that because I'm drunk".
So...EXPLOSION! and then a knock on the door, and it's that guy, and now I'm all like "Oh, yeah, hey, I wasn't lying when I said we should hang, forreal, but this pyrex dish just exploded in my kitchen, like literally, and broth and orzo and vegetables are everywhere, so this is a bad time dude, I'm sorry."
So fuck you, pyrex. That guy seemed pretty cool and I could have had a new friend.
posted by spikeleemajortomdickandharryconnickjrmints at 9:06 AM on December 11, 2010 [33 favorites]
So the hot pyrex dish is now sitting on top of the stove, and I accidentally turn on the burner that's under it, instead of the burner that's under the pot with the soup. Next, I take cold broth and pour it into the very hot pyrex dish, and it doesn't just crack, it doesn't just shatter, it EXPLODES!
Glass goes everywhere. At that moment I got a knock on on my door from a guy I met at a party and found out that he lived two blocks from me, and I'm all like "Oh yeah dude, stop by anytime, I usually work from home, seriously, let's hang, I'm not just saying that because I'm drunk".
So...EXPLOSION! and then a knock on the door, and it's that guy, and now I'm all like "Oh, yeah, hey, I wasn't lying when I said we should hang, forreal, but this pyrex dish just exploded in my kitchen, like literally, and broth and orzo and vegetables are everywhere, so this is a bad time dude, I'm sorry."
So fuck you, pyrex. That guy seemed pretty cool and I could have had a new friend.
posted by spikeleemajortomdickandharryconnickjrmints at 9:06 AM on December 11, 2010 [33 favorites]
I almost wish I hadn't just given away those two old Pyrex casserole pans in the move.
posted by immlass at 9:07 AM on December 11, 2010
posted by immlass at 9:07 AM on December 11, 2010
I worked in the glass industry for 5 years when I was first starting out. One thing I learned is that tempered glass can be some temperamental shit.
Tempering glass makes it stronger by increasing the surface tension. It makes the glass stronger, but it also makes it more brittle. Because of the tension, when the glass breaks it more or less explodes. Thinner glass tends to break into lots of small reasonably-unsharp pieces - that's why door glazing is required to be tempered.
Thicker glass (like, say, glass used in bakeware) will fracture the same way, but is more likely to create shards than pieces.
posted by Benny Andajetz at 9:10 AM on December 11, 2010 [5 favorites]
Tempering glass makes it stronger by increasing the surface tension. It makes the glass stronger, but it also makes it more brittle. Because of the tension, when the glass breaks it more or less explodes. Thinner glass tends to break into lots of small reasonably-unsharp pieces - that's why door glazing is required to be tempered.
Thicker glass (like, say, glass used in bakeware) will fracture the same way, but is more likely to create shards than pieces.
posted by Benny Andajetz at 9:10 AM on December 11, 2010 [5 favorites]
Hmm. Google tells me that while Pyrex baking dishes aren't made out of borosilicate anymore, Corning still makes laboratory glass out of that material. So...if I switch to cooking in Erlenmeyer flasks and beakers, I should be fine. This is clearly the solution.
posted by Tesseractive at 9:11 AM on December 11, 2010 [15 favorites]
posted by Tesseractive at 9:11 AM on December 11, 2010 [15 favorites]
In a bit of good news, CorningWare is now once again available in proper pyroceramic glass. That had been discontinued for several years in favor of a cheaper stoneware version.
posted by jedicus at 9:20 AM on December 11, 2010
posted by jedicus at 9:20 AM on December 11, 2010
Does anyone know if this applies to lab glasswear? Pyrex is one of the big suppliers of lab glasswear, and we are often heating things up to quite high temperatures, letting it cool for a bit, and then plunging it into an icebaths, which makes temperatures resistance rather important.
posted by Canageek at 9:38 AM on December 11, 2010
posted by Canageek at 9:38 AM on December 11, 2010
I've had pyrex explode too. That's some scary shit and a pain to clean. Since then I've stayed away from pyrex, but it's good to know what exactly to avoid now.
posted by Kattullus at 9:39 AM on December 11, 2010
posted by Kattullus at 9:39 AM on December 11, 2010
Is my glass waterpipe safe?
posted by furiousxgeorge at 9:41 AM on December 11, 2010 [1 favorite]
posted by furiousxgeorge at 9:41 AM on December 11, 2010 [1 favorite]
I knew that lots of stuff under the pyrex brand name wasn't borosilicate anymore which is fine, I just don't use the other stuff inside the oven, but I didn't realize that they don't offer any borosilicate at all any more. That really sucks.
posted by paisley henosis at 9:44 AM on December 11, 2010
posted by paisley henosis at 9:44 AM on December 11, 2010
I'm going to subscribe to Consumer Reports now. It turns out they're a nonprofit, and they protect me from exploding glass!
posted by Monochrome at 9:45 AM on December 11, 2010 [2 favorites]
posted by Monochrome at 9:45 AM on December 11, 2010 [2 favorites]
I think it's kind of telling that in the modern US business environment, the correct reaction to everyone thinking you make a good product is to stop doing it because that's cheaper. Then, you live off the name for a few years, until everyone finds out, and then wonder why your profits mysteriously go away
posted by Mitrovarr at 9:46 AM on December 11, 2010 [55 favorites]
posted by Mitrovarr at 9:46 AM on December 11, 2010 [55 favorites]
If you're over 30 you can test this theory. The Pyrex measuring cups of my youth would bounce. The modern ones, not so much.
posted by DarlingBri at 9:47 AM on December 11, 2010 [1 favorite]
posted by DarlingBri at 9:47 AM on December 11, 2010 [1 favorite]
So, isn't anyone making UK Pyrex available for import? Also: wouldn't it make more sense to over 'delux' borosilicate pans as an option?
Also: What glass resists breaking the most? I may be sick of wasting money due to dropped beakers and flasks. *cough*
posted by Canageek at 9:57 AM on December 11, 2010
Also: What glass resists breaking the most? I may be sick of wasting money due to dropped beakers and flasks. *cough*
posted by Canageek at 9:57 AM on December 11, 2010
Excellent and well-regarded old brand takes a sudden nosedive in quality?
Aha! I smell a r--, er, private equity deal, of course (same outfit owns Corning, coincidentally).
Exactly what happened to Simmons mattresses.
posted by jamjam at 9:58 AM on December 11, 2010 [12 favorites]
Aha! I smell a r--, er, private equity deal, of course (same outfit owns Corning, coincidentally).
Exactly what happened to Simmons mattresses.
posted by jamjam at 9:58 AM on December 11, 2010 [12 favorites]
It's telling that the European operations were acquired by a French company, which is committed to making the damned things properly.
I have invented a new phrase to describe American entities which give away everything that made them worth a damn to begin with: "Pulling an Obama."
posted by 1adam12 at 10:00 AM on December 11, 2010 [9 favorites]
I have invented a new phrase to describe American entities which give away everything that made them worth a damn to begin with: "Pulling an Obama."
posted by 1adam12 at 10:00 AM on December 11, 2010 [9 favorites]
Dammit can't we do anything right anymore?
posted by wuwei at 10:07 AM on December 11, 2010 [3 favorites]
posted by wuwei at 10:07 AM on December 11, 2010 [3 favorites]
Does anyone know if this applies to lab glasswear?
I checked the Pyrex web site and the labware section immediately sends me over to Corning Life Sciences. So I'm guessing that Corning makes all the Pyrex labware. And since all Corning glassware are made of borosilicate, the lab is safe from exploding glass. Which is good because flaming beakers of ethanol is kind of common in my lab.
The crystallizing dishes look like they can be used to make casseroles. :)
posted by cosmic_shoals at 10:13 AM on December 11, 2010
I checked the Pyrex web site and the labware section immediately sends me over to Corning Life Sciences. So I'm guessing that Corning makes all the Pyrex labware. And since all Corning glassware are made of borosilicate, the lab is safe from exploding glass. Which is good because flaming beakers of ethanol is kind of common in my lab.
The crystallizing dishes look like they can be used to make casseroles. :)
posted by cosmic_shoals at 10:13 AM on December 11, 2010
Vintage Pyrex is cheap, easy to find...
But it isn't easy to know how old it should be to be borosilicate glass. I read that article yesterday, and there are all kinds of different claims about when they switched to soda-lime glass. 60 years ago? 30 years? 12 years? All those numbers are put out by people who presumably should know.
Pyrex Classic is a Euro brand and is borosilicate, but not sold in the US. Arcuisine Elegance is a French brand of borosilicate that is sold in the US. It's about three times as expensive as domestic Pyrex.
posted by Kirth Gerson at 10:14 AM on December 11, 2010 [1 favorite]
But it isn't easy to know how old it should be to be borosilicate glass. I read that article yesterday, and there are all kinds of different claims about when they switched to soda-lime glass. 60 years ago? 30 years? 12 years? All those numbers are put out by people who presumably should know.
Pyrex Classic is a Euro brand and is borosilicate, but not sold in the US. Arcuisine Elegance is a French brand of borosilicate that is sold in the US. It's about three times as expensive as domestic Pyrex.
posted by Kirth Gerson at 10:14 AM on December 11, 2010 [1 favorite]
I think it's kind of telling that in the modern US business environment, the correct reaction to everyone thinking you make a good product is to stop doing it because that's cheaper.
Yep. The idea that the market will correct everything seems to miss the fact that we don't get an information-perfect market - you can score big profit while consumers are trying to catch up on your actual quality vs. your standing reputation. (Services seem to be rife with this business model, especially if they get you to sign on a contract.)
In the meantime, broken glass for everyone!
posted by yeloson at 10:23 AM on December 11, 2010 [13 favorites]
Yep. The idea that the market will correct everything seems to miss the fact that we don't get an information-perfect market - you can score big profit while consumers are trying to catch up on your actual quality vs. your standing reputation. (Services seem to be rife with this business model, especially if they get you to sign on a contract.)
In the meantime, broken glass for everyone!
posted by yeloson at 10:23 AM on December 11, 2010 [13 favorites]
Kirth Gerson: But it isn't easy to know how old it should be to be borosilicate glass.
From what I've seen, you can tell the difference visually. Borosilicate glass is yellowish-orange, and soda-lime is blue-green.
Of course, this only works if it isn't dyed.
posted by Mitrovarr at 10:24 AM on December 11, 2010
From what I've seen, you can tell the difference visually. Borosilicate glass is yellowish-orange, and soda-lime is blue-green.
Of course, this only works if it isn't dyed.
posted by Mitrovarr at 10:24 AM on December 11, 2010
I'm not sure I see the big deal here. Borosilicate glass has slightly better thermal shock resistance. Tempered soda lime glass has slightly better impact resistance. Consumer Reports only tested thermal shock resistance. Note that they said that all dishes, even the European borosilicate ones, failed at 500 degrees. Don't plunge hot glassware into cold water seems like a simple rule.
posted by JackFlash at 11:05 AM on December 11, 2010
posted by JackFlash at 11:05 AM on December 11, 2010
If you're an idiot like me, even the older Pyrex can be dangerous. I was roasting a couple of eggplants in Pyrex baking dish to make baba ganoush one evening. What I didn't know was that my elderly oven had decided to stop working properly. To be exact the thermostat crapped out. In stead of keep in at a steady 400 degrees, it just kept getting hotter and hotter. When I finally pulled the dish out the eggplants were black and hissing.
So I poured cold water over them. The resulting explosion was frightening.
It's a lucky thing that I wear glasses. My right hand and face had several small cuts. I might have lost my sight. I'm guessing that the Pyrex was over 600 degrees Fahrenheit.
Do not try this at home.
posted by Splunge at 11:09 AM on December 11, 2010 [2 favorites]
So I poured cold water over them. The resulting explosion was frightening.
It's a lucky thing that I wear glasses. My right hand and face had several small cuts. I might have lost my sight. I'm guessing that the Pyrex was over 600 degrees Fahrenheit.
Do not try this at home.
posted by Splunge at 11:09 AM on December 11, 2010 [2 favorites]
If you really want temperature resistance you could try to find someone that makes quartz crystal dishes. It has a very, very small thermal expansion coefficient, so we use it for when we are heating things to 800C or higher (That temperature could be wrong, I'm trying to remember some things I did 2 years ago). As I recall it is fairly shatter resistant as well, though it is probably far, far more expensive than anything on the list, to the point I'd be amazed if anyone made glassware out of it. If you have large sums of money burning a hole in your pocket however...
posted by Canageek at 11:12 AM on December 11, 2010
posted by Canageek at 11:12 AM on December 11, 2010
If you really want temperature resistance you could try to find someone that makes quartz crystal dishes.
The outstanding performance of quartz barbecue plate:
1, far-infrared emission of the crystal can eliminate the odor of meat.
2. Crystal barbecue like jewel can bake appetizing food.
3, barbecue plate crystals with a thermostat can keep meat fresh.
4. Crystal can not be wetlands and sticky board, which also serves meals easy to clean. It has
silica content of accounting for more than 99% of the original crystal.
5. High-purity crystal completely different from the glass (such as fiber crystal clouds).
6, mineral crystal high temperature and difficult to chemical reaction.
We can according to the different needs of customers to develop appropriate specifications.
See also these two crystal baking plates.
Crystal plate for roasting is a kind of environmental, fashionable and green present of high quality
posted by zippy at 11:44 AM on December 11, 2010 [1 favorite]
The outstanding performance of quartz barbecue plate:
1, far-infrared emission of the crystal can eliminate the odor of meat.
2. Crystal barbecue like jewel can bake appetizing food.
3, barbecue plate crystals with a thermostat can keep meat fresh.
4. Crystal can not be wetlands and sticky board, which also serves meals easy to clean. It has
silica content of accounting for more than 99% of the original crystal.
5. High-purity crystal completely different from the glass (such as fiber crystal clouds).
6, mineral crystal high temperature and difficult to chemical reaction.
We can according to the different needs of customers to develop appropriate specifications.
See also these two crystal baking plates.
Crystal plate for roasting is a kind of environmental, fashionable and green present of high quality
posted by zippy at 11:44 AM on December 11, 2010 [1 favorite]
The big deal is that bakeware is going to experience thermal shock in its normal day-to-day use. If you set it down in your preheated oven, the air in there may be the same temperature as the oven rack you set it on, but the oven rack will transmit heat into your bakeware much faster. If you pull it out and set it on your counter top without some kind of insulating hot pad, the counter top will pull head out of it much faster.
Plunging a 500° dish into cold water is a little like shooting a car into a giant block of granite at 150 mph using a aircraft carriers steam catapult. Yes, under those sorts of conditions the passengers are pretty much doomed no matter what they're driving. While true, it doesn't simulate normal conditions.
Personally, I like stainless steel.
posted by Kid Charlemagne at 12:04 PM on December 11, 2010 [2 favorites]
Plunging a 500° dish into cold water is a little like shooting a car into a giant block of granite at 150 mph using a aircraft carriers steam catapult. Yes, under those sorts of conditions the passengers are pretty much doomed no matter what they're driving. While true, it doesn't simulate normal conditions.
Personally, I like stainless steel.
posted by Kid Charlemagne at 12:04 PM on December 11, 2010 [2 favorites]
I love glass. If you're ever in Corning, NY, be sure to visit their glass museum.
And if you have any of the old Corning Visions stuff you want to get rid of, let me know.
posted by box at 12:15 PM on December 11, 2010 [2 favorites]
And if you have any of the old Corning Visions stuff you want to get rid of, let me know.
posted by box at 12:15 PM on December 11, 2010 [2 favorites]
Is my glass waterpipe safe?
Every glassblower I've talked to uses proper borosilicate glass for their pipes.
posted by clarknova at 12:18 PM on December 11, 2010 [1 favorite]
Every glassblower I've talked to uses proper borosilicate glass for their pipes.
posted by clarknova at 12:18 PM on December 11, 2010 [1 favorite]
You're not supposed to put pyrex from 450 degree oven on WET countertop. I'm pretty sure they explicit say that on warning labels when you buy Pyrex containers.
Yeah, and the existence of warnings on cigarettes means tobacco companies are blameless!
posted by JHarris at 1:36 PM on December 11, 2010 [2 favorites]
Yeah, and the existence of warnings on cigarettes means tobacco companies are blameless!
posted by JHarris at 1:36 PM on December 11, 2010 [2 favorites]
I read that article yesterday, and there are all kinds of different claims about when they switched to soda-lime glass. 60 years ago? 30 years? 12 years?
Ummm, this? I'm trying to remember exactly when it was that someone first pointed out to me that there was difference between Pyrex brand glassware and actual Pyrex glassware, but it's gotta be at least 15 years ago. I even vaguely remember someone teaching me how to tell the difference, but I forget the details.
As far as I knew this was common knowledge, and I'm genuinely surprised to find out it isn't.
posted by Pinback at 2:14 PM on December 11, 2010 [1 favorite]
Ummm, this? I'm trying to remember exactly when it was that someone first pointed out to me that there was difference between Pyrex brand glassware and actual Pyrex glassware, but it's gotta be at least 15 years ago. I even vaguely remember someone teaching me how to tell the difference, but I forget the details.
As far as I knew this was common knowledge, and I'm genuinely surprised to find out it isn't.
posted by Pinback at 2:14 PM on December 11, 2010 [1 favorite]
For no reason that i know of, i had an Anchor Hocking casserole full of macaroni and cheese explode in my oven two or three years ago. I'd used it a million times before without a problem. The company told me it must have had stress fractures, which made no sense to me, considering it didnt just crack, that shit was EVERYWHERE... Scared the crap out of my poor Lab who was sleeping in the kitchen at the time, too.
posted by OneMonkeysUncle at 2:28 PM on December 11, 2010
posted by OneMonkeysUncle at 2:28 PM on December 11, 2010
Dammit can't we do anything right anymore?
We sure can, as long as "right" is defined as "maximizing short-term return on capital."
posted by Kadin2048 at 2:45 PM on December 11, 2010 [6 favorites]
We sure can, as long as "right" is defined as "maximizing short-term return on capital."
posted by Kadin2048 at 2:45 PM on December 11, 2010 [6 favorites]
I remember my set of Corning Visions (now gone to that Goodwill store in the sky). They heated up very quickly and always ran excessively hot, so much that I had to alter recipes and cooking times/temperatures when I would use them.
posted by sundrop at 3:06 PM on December 11, 2010
posted by sundrop at 3:06 PM on December 11, 2010
Yikes. This happened to me the other day. I cooked up some noodles in the microwave and then brought them out and--admittedly, not thinking--drained the noodles and put a bit of lukewarm tapwater in to give them a rinse.
CRACK!
Luckily it was over the sink; the bowl shattered, and what pieces were still large had massive cracks all over it, and they fell apart even more between the sink and the bin. It was quite cool to watch, actually.
I won't be doing that again... and now I have to buy another pyrex bowl, and I can't afford it :(
posted by owlrigh at 3:38 PM on December 11, 2010
CRACK!
Luckily it was over the sink; the bowl shattered, and what pieces were still large had massive cracks all over it, and they fell apart even more between the sink and the bin. It was quite cool to watch, actually.
I won't be doing that again... and now I have to buy another pyrex bowl, and I can't afford it :(
posted by owlrigh at 3:38 PM on December 11, 2010
I've wondered for many years if capitalism might actually work well if everyone (as in 100% of the population) had some sort of all-inclusive Consumer Reports app on their phones, which they were trained from birth to religiously check before paying for any item or service of any kind. Of course, then companies would try to game the system through bribes of some kind, and would probably succeed, and after some major scandal, some people would leave and use a different consumer reporting company, and this trend would continue, and soon you would need a Consumer Reports Reports, but then the consumer reporting companies would figure out how to game this, etc.
But we'd sure have a lot of jobs!
posted by Xezlec at 3:44 PM on December 11, 2010 [12 favorites]
But we'd sure have a lot of jobs!
posted by Xezlec at 3:44 PM on December 11, 2010 [12 favorites]
I have a large collection of Corning Visions which is pretty complete in the amber color, except for the medium sized frying pan that we have broken at least 7 times by dropping it or banging it into something.
My mate doesn't like them for about the same reasons as sundrop. I think the problem there is that heat radiation from electric burners and electric oven elements shines through them without being absorbed, and can burn your food as if you had it under the broiler, only from underneath.
The main problem I have with them is that the lids fit poorly both horizontally and vertically-- in the sense that they slop from side to side way too much and do not seal well-- and the sealing aspect is perfectly deliberate, too, as witness the three bumps 120 degrees apart on the part of the lid which rests against the base. All the ads showed them being used with gas, as I recall.
I think they did that to prevent the lid from rattling against the base when steam escaped and ultimately cracking that base. I think they should've used metal rims shrunk onto glass lids instead, though there are drawbacks to that, as well.
The Visions stuff still has something going for it, however, even beyond the appeal of cooking in an almost completely chemically inert vessel, and I can't bring myself to get rid of it.
The roasting pans and 5 liter stock pots are truly beautiful.
posted by jamjam at 4:00 PM on December 11, 2010 [1 favorite]
My mate doesn't like them for about the same reasons as sundrop. I think the problem there is that heat radiation from electric burners and electric oven elements shines through them without being absorbed, and can burn your food as if you had it under the broiler, only from underneath.
The main problem I have with them is that the lids fit poorly both horizontally and vertically-- in the sense that they slop from side to side way too much and do not seal well-- and the sealing aspect is perfectly deliberate, too, as witness the three bumps 120 degrees apart on the part of the lid which rests against the base. All the ads showed them being used with gas, as I recall.
I think they did that to prevent the lid from rattling against the base when steam escaped and ultimately cracking that base. I think they should've used metal rims shrunk onto glass lids instead, though there are drawbacks to that, as well.
The Visions stuff still has something going for it, however, even beyond the appeal of cooking in an almost completely chemically inert vessel, and I can't bring myself to get rid of it.
The roasting pans and 5 liter stock pots are truly beautiful.
posted by jamjam at 4:00 PM on December 11, 2010 [1 favorite]
Personally, I like stainless steel.
I agree. Glass is for serving, metal is for cooking.
I've got some commercial steam table type pans that I use, occasionally over a gas flame. If they run dry, they will twist up into surprisingly odd shapes. When they cool off, back to normal.
posted by gjc at 7:18 PM on December 11, 2010
I agree. Glass is for serving, metal is for cooking.
I've got some commercial steam table type pans that I use, occasionally over a gas flame. If they run dry, they will twist up into surprisingly odd shapes. When they cool off, back to normal.
posted by gjc at 7:18 PM on December 11, 2010
The company told me it must have had stress fractures, which made no sense to me, considering it didnt just crack, that shit was EVERYWHERE
That's how tempered glass fails, though: it doesn't crack, it self-pulverizes as all of the intentionally built-in stresses release. This is sometimes a really desirable trait because it means you end up with those little glass cubes instead of giant razor-scythes.
posted by hattifattener at 11:41 PM on December 11, 2010
That's how tempered glass fails, though: it doesn't crack, it self-pulverizes as all of the intentionally built-in stresses release. This is sometimes a really desirable trait because it means you end up with those little glass cubes instead of giant razor-scythes.
posted by hattifattener at 11:41 PM on December 11, 2010
Without wishing to shit in this thread, this isn't a new issue. And there are elements of urban myth to how it's usually presented.
ConsumerAffairs.com stories of exploding pyrex going back to 2005.
Pyrexlove.com on whether it's safe to use your old pyrex in the oven.
Snopes.
Also, I've got a bit of anecdata..
I'm the custodian of the world's largest collection of Australian made pyrex ("Agee Pyrex"). I use as much of it as I can, as often as I can. I also possess and use a lot of American (Corning) and English (Jobling or JAJ) Pyrex. Over the past 20 years or so, I (at a guess) would have cooked with old pyrex at least 2000 times. I've also done quite a lot of research into the various Pyrexes. I know a thing or two about them.
I could literally write thousands of words about this, but there's only really two specific things that need to be shared.
Firstly, with the exception of Arc's "Pyrex Classic" line, no manufacturer of brand name Pyrex anywhere in the world has regularly used borosilicate glass for domestic oven/kitchen/tableware since the late 50's. There's the odd other exception in stove top products. But speaking generally, everything branded "Pyrex" has been soda lime for 50 years. Thus if your new Pyrex is exploding on you at a greater rate than your old pyrex, it's probably a case of new soda lime glass being crappier than old soda lime glass. Unless you collect and cook with antiques, you're unlikely to have any borosilicate for comparison.
Secondly, in my own experience, old borosilicate glass Pyrex is just as prone to dramatic shattering as soda lime glass Pyrex - it never was made particularly well, and it's getting old. Even with pieces in excellent condition, it's very common to see manufacturing flaws in older pyrex - cooling ripples, small internal flaws, bubbles, and seeds. It's also very common to see flaws from wear - scratches, chips, internal cracks, impact flaws, etc. 50-60+ years of use will do that to a piece of kitchen glass. Both manufacturing flaws and wear weaken the glass. They make it prone to shattering violently as a result of thermal shock, particularly thermal down shock.
I explain this to other collectors and on glass forums all the time, and at the end of the day, all I can really say is this.. I have hundreds of pieces of Pyrex. Many are made from borosilicate glass. Many are made from soda lime glass. I like to use them. I take care doing that. But sometimes I lose them. And the failure rate over the past two decades or so has probably been equal. Old borosilicate and soda lime glass are equally likely to shatter from thermal shock, usually on cooling.
As a footnote for anyone reading this who wants indestructible "glass" kitchenware that can move comfortably between stove top, oven and freezer - buy old Corningware. The manufacturers' reps who used to sell it would demonstrate it by taking it out of a freezer, heating it red hot with a blow torch, then dumping it into a bucket of ice water. And it would be fine. It's also expected to have a useful life stretching into the hundreds of years. Or so I've been told. (But be warned that the lids are soda lime pyrex).
posted by Ahab at 12:51 AM on December 12, 2010 [49 favorites]
ConsumerAffairs.com stories of exploding pyrex going back to 2005.
Pyrexlove.com on whether it's safe to use your old pyrex in the oven.
Snopes.
Also, I've got a bit of anecdata..
I'm the custodian of the world's largest collection of Australian made pyrex ("Agee Pyrex"). I use as much of it as I can, as often as I can. I also possess and use a lot of American (Corning) and English (Jobling or JAJ) Pyrex. Over the past 20 years or so, I (at a guess) would have cooked with old pyrex at least 2000 times. I've also done quite a lot of research into the various Pyrexes. I know a thing or two about them.
I could literally write thousands of words about this, but there's only really two specific things that need to be shared.
Firstly, with the exception of Arc's "Pyrex Classic" line, no manufacturer of brand name Pyrex anywhere in the world has regularly used borosilicate glass for domestic oven/kitchen/tableware since the late 50's. There's the odd other exception in stove top products. But speaking generally, everything branded "Pyrex" has been soda lime for 50 years. Thus if your new Pyrex is exploding on you at a greater rate than your old pyrex, it's probably a case of new soda lime glass being crappier than old soda lime glass. Unless you collect and cook with antiques, you're unlikely to have any borosilicate for comparison.
Secondly, in my own experience, old borosilicate glass Pyrex is just as prone to dramatic shattering as soda lime glass Pyrex - it never was made particularly well, and it's getting old. Even with pieces in excellent condition, it's very common to see manufacturing flaws in older pyrex - cooling ripples, small internal flaws, bubbles, and seeds. It's also very common to see flaws from wear - scratches, chips, internal cracks, impact flaws, etc. 50-60+ years of use will do that to a piece of kitchen glass. Both manufacturing flaws and wear weaken the glass. They make it prone to shattering violently as a result of thermal shock, particularly thermal down shock.
I explain this to other collectors and on glass forums all the time, and at the end of the day, all I can really say is this.. I have hundreds of pieces of Pyrex. Many are made from borosilicate glass. Many are made from soda lime glass. I like to use them. I take care doing that. But sometimes I lose them. And the failure rate over the past two decades or so has probably been equal. Old borosilicate and soda lime glass are equally likely to shatter from thermal shock, usually on cooling.
As a footnote for anyone reading this who wants indestructible "glass" kitchenware that can move comfortably between stove top, oven and freezer - buy old Corningware. The manufacturers' reps who used to sell it would demonstrate it by taking it out of a freezer, heating it red hot with a blow torch, then dumping it into a bucket of ice water. And it would be fine. It's also expected to have a useful life stretching into the hundreds of years. Or so I've been told. (But be warned that the lids are soda lime pyrex).
posted by Ahab at 12:51 AM on December 12, 2010 [49 favorites]
For you thrift shop hunters, I bet you can immediately distinguish borosilicate glass from tempered glass with a pair of crossed polarizers. Put one polarizer in front of the glass and one behind. You want to view light that passes through: |polarizer| -> |glass| -> |polarizer|.
Tempered glass will have a regular pattern of stresses that will appear as colorful distortions when viewed through the polarizers. I'd expect something like a checkerboard pattern, with one or two inch spacing between the distortions. Old school pyrex, which was not tempered, will probably also show some colorful distortions, but they won't have the regular spacing of the tempered stuff.
To understand exactly what you are looking for, it helps to know a bit about the tempering process. First the glass object passes through a furnace which heats it above its annealing point. Then the surface of the glass is rapidly cooled with jets of air. This rapid surface cooling produces the stresses that show up with the polarizers. The pattern of distortions is due to the placement of the air jets. Manufacturers generally arrange the air nozzles in some sort of grid, hence the checkerboard.
If you wear polarized sunglasses, you've probably seen this same checkerboard pattern on the rear windows of cars. The pattern is only visible in certain lighting conditions because you're relying on glare reflected off the window to act as the second polarizer.
(Note that I haven't actually performed this experiment, so I'm not sure how well it works in practice. If anyone tries this, please post the results.)
posted by ryanrs at 3:56 AM on December 12, 2010 [8 favorites]
Tempered glass will have a regular pattern of stresses that will appear as colorful distortions when viewed through the polarizers. I'd expect something like a checkerboard pattern, with one or two inch spacing between the distortions. Old school pyrex, which was not tempered, will probably also show some colorful distortions, but they won't have the regular spacing of the tempered stuff.
To understand exactly what you are looking for, it helps to know a bit about the tempering process. First the glass object passes through a furnace which heats it above its annealing point. Then the surface of the glass is rapidly cooled with jets of air. This rapid surface cooling produces the stresses that show up with the polarizers. The pattern of distortions is due to the placement of the air jets. Manufacturers generally arrange the air nozzles in some sort of grid, hence the checkerboard.
If you wear polarized sunglasses, you've probably seen this same checkerboard pattern on the rear windows of cars. The pattern is only visible in certain lighting conditions because you're relying on glare reflected off the window to act as the second polarizer.
(Note that I haven't actually performed this experiment, so I'm not sure how well it works in practice. If anyone tries this, please post the results.)
posted by ryanrs at 3:56 AM on December 12, 2010 [8 favorites]
I'm looking at a ton of pyrex right now ryan, and would love to try that, but I've got no polarizing whatsits..
There's a quick and nasty way to tell with English and Australian Pyrex, which unfortunately doesn't apply to Corning Pyrex after 1934. The melt for borosilicate Pyrex was really dense and held too many bubbles. To get rid of the bubbles, the manufacturers used large amounts of arsenic as a refining agent (Corning stopped in 1934, but JAJ and AGM/ACI continued).
This gave a distinctive yellow (see the comment about arsenic below photo) or golden tint to the glass (again see the comment, and also the one further down by Mackem54, who's a former JAJ employee). When JAJ in the UK and ACI in Australia switched over to soda lime glass, they needed less arsenic, and there was a color change towards light gray in English pyrex (note the color of the lids in the catalog), and a much lighter yellow, faint blue, or very light greenish hue to Australian Agee and Crown Pyrex.
The other dead giveaway is that if you have opal (white) pyrex from anywhere, it's soda lime. Corning introduced it in 1945, JAJ in the late 50's and ACI in about 1960 or 61. It was Corning's tempered development of the Macbeth-Evans Glass Co's "Monax" soda lime glass.
posted by Ahab at 5:53 AM on December 12, 2010 [2 favorites]
There's a quick and nasty way to tell with English and Australian Pyrex, which unfortunately doesn't apply to Corning Pyrex after 1934. The melt for borosilicate Pyrex was really dense and held too many bubbles. To get rid of the bubbles, the manufacturers used large amounts of arsenic as a refining agent (Corning stopped in 1934, but JAJ and AGM/ACI continued).
This gave a distinctive yellow (see the comment about arsenic below photo) or golden tint to the glass (again see the comment, and also the one further down by Mackem54, who's a former JAJ employee). When JAJ in the UK and ACI in Australia switched over to soda lime glass, they needed less arsenic, and there was a color change towards light gray in English pyrex (note the color of the lids in the catalog), and a much lighter yellow, faint blue, or very light greenish hue to Australian Agee and Crown Pyrex.
The other dead giveaway is that if you have opal (white) pyrex from anywhere, it's soda lime. Corning introduced it in 1945, JAJ in the late 50's and ACI in about 1960 or 61. It was Corning's tempered development of the Macbeth-Evans Glass Co's "Monax" soda lime glass.
posted by Ahab at 5:53 AM on December 12, 2010 [2 favorites]
Polarized sunglasses should work. (Not sure about circularly polarized camera filters, though.)
posted by ryanrs at 6:09 AM on December 12, 2010
posted by ryanrs at 6:09 AM on December 12, 2010
You can also buy cheap polarizing novelty glasses at pretty much any science museum gift shop for a couple bucks.
posted by klangklangston at 9:27 AM on December 12, 2010
posted by klangklangston at 9:27 AM on December 12, 2010
It's quite amusing hearing people pining for the good old days of Pyrex before corporate corruption when it turns out that the good old days were the 1940s before they were born and it turns out they have been using the corrupt glassware their entire lives and didn't know it. The internets can cause people to get up in arms about the funniest things. Next up, a replay of how Mr. Clean's Magic Eraser is poisonous.
posted by JackFlash at 9:44 AM on December 12, 2010
posted by JackFlash at 9:44 AM on December 12, 2010
Cookware snobs have claimed this for years now--I can't remember if I've seen this discussed on Chowhound or food_porn or what, but people have grumbled and sworn up and down they could tell a difference in quality for years. On the personal front, I have a measuring cup from my mother that is much better quality than some of the Pyrex I received when I got married last year. Very sad. And someone mentioned the MO of establishing awesome name brand recognition and then coasting on that until people catch on, rinse, repeat...KitchenAid and Cuisinart have both been well known for pulling that shit in the last 15 years or so; KA stand mixers became such a sought after item and then sometime in the '80s or early '90s people began calling attention to the fact the parts had become complete shit, stuff like plastic moving parts and housing and whatnot, and they scrambled to reestablish themselves. That sort of thing pisses me off to no end.
posted by ifjuly at 11:09 AM on December 12, 2010 [1 favorite]
posted by ifjuly at 11:09 AM on December 12, 2010 [1 favorite]
On mixers, I still regularly use a 1948 Sunbeam A9-B Mixmaster. There's no way I could make bread dough with it without burning out the motor, but it'll do everything else I want it to. At 62 years old, that's good enough for me. But email messages coming through from WACEM board posts today tell me that the way to go for a currently manufactured, robust, powerful, easily maintained, commercial mixer that's still appropriate for a home kitchen is the Hobart N50. It looks and sounds like a seriously functional old school machine, but apparently they cost quite a lot..
posted by Ahab at 11:37 AM on December 12, 2010
posted by Ahab at 11:37 AM on December 12, 2010
It's quite amusing hearing people pining for the good old days of Pyrex before corporate corruption when it turns out that the good old days were the 1940s before they were born and it turns out they have been using the corrupt glassware their entire lives and didn't know it.
I don't know if that's entirely clear. The CR article says that's World Kitchen's claim, but that there are conflicting accounts from people at Corning, which sold the Pyrex brand to World Kitchen:
posted by palliser at 3:02 PM on December 12, 2010
I don't know if that's entirely clear. The CR article says that's World Kitchen's claim, but that there are conflicting accounts from people at Corning, which sold the Pyrex brand to World Kitchen:
It's not clear when the switch occurred. Anchor Hocking spokeswoman Barbara Wolf says borosilicate glass was phased out by the industry by the early 1980s. World Kitchen vice president Jim Aikins says Pyrex glass bakeware sold in the U.S. has consistently been made of soda lime glass that has been strengthened through thermal tempering at the Charleroi plant for about 60 years.I don't know if Ahab's information comes from World Kitchen, or is from another source that has taken Corning's claims into account.
Sarah Horvath, a Corning spokeswoman, says Corning made Pyrex out of both soda lime and borosilicate at several locations before selling the U.S. business to World Kitchen in 1998, but provided no more details. P. Bruce Adams, formerly an executive scientist at Corning, says that borosilicate was still being used to make Pyrex when he retired in 1987.
In any case, European glass bakeware dishes that we purchased for testing were made from borosilicate.
posted by palliser at 3:02 PM on December 12, 2010
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