Just curious if you have experience with pouring boiling water into glass jars?

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I'm just looking for practical real-world experience.
Today I had a bit of old tea powder left in a Lipton powdered iced tea jar.
Instead of throwing it out or chipping it out, I simply poured boiling water into it and drank it from the jar.
Since I half expected the glass jar to break, I did this in the sink - but to my surprise, the glass held the just-boiled water.
I realize that glass can be made out of many materials (e.g., Pyrex) ... but I wonder ...
Is this the general experience that typical American glass jars hold up to boiling water?
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Chuck Banshee wrote:

Dunno in general, but with canning jars (i.e., Kerr) that's how you sterilize them.
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On 1/6/2012 8:27 PM, Chuck Banshee wrote:


http://www.youtube.com/watch?v=UyhdMa1ikKM

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On Fri, 06 Jan 2012 21:00:46 -0500, Betelgeuse wrote:

Review: Over 150 incidents of glass 'bakeware' shattered (some with serious injuries).
Borosilicon (often made in Europe) versus soda lime (which is more shatter resistant).
They filled bakeware with dry sand, baked at 450 degrees F for 80 minutes, and then put it on wet graniteand.
The result was that 10/10 times the American-made soda lime bakeware broke while the European Borosilicon didn't break (but most did at 500 degrees).
Revealingly, the ancient American Borosilicon did last at 500 degrees.
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Didnt know there was soda glass bakeware made in USA. Pyrex isthe only glass bakeware I know of.
Jimmie
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On Sun, 08 Jan 2012 15:29:53 -0800, JIMMIE wrote:

The Consumer Reports article implied there is Anchor Hockings and Pyrex and that Pyrex is no longer made by Corning (if I remember correctly).
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On Sat, 7 Jan 2012 01:27:06 +0000 (UTC), Chuck Banshee

Glass jars can easily take the 200 or so degrees of hot water. What will do them in is thermal shock where it is heated too quickly in one spot compared to other spots. As in a flame, for instance. or freezer to oven or reverse.
Glass jars are heated fairly high when filled with the contents and sealed. Heat killing bacteria is what allows it to keep product safe.
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I agree. I've poured boiling water into glass containers over the years and never saw one shatter either. I still do it carfully though. I think the reverse is worse, ie quickly quenching a hot glass.
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Take that jar out of the freezed and splash some boiling water into it, and it will react totally differently!!
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On Sat, 07 Jan 2012 01:27:06 +0000, Chuck Banshee wrote:

An unexpected bonus was the fact that the glue under the wrap-around label heated up enough to be easily balled off with a kitchen utensil.
Maybe we accidentally found a way to remove the under-label glue without solvents!
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Like most materials, glass expands when heated. Heat breaks glass vessels when the glass is nonuniform, i.e. has varying densities at various places. If some parts expand faster than others, this introduces stresses that may break the vessel. It is generally supposed that older glass vessels are more uniform than modern ones, thus can accept more heat without breaking.
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Well, not all "glass" is the same.
Pure quartz glass has a very low thermal coefficient of expansion. Standard "Soda-Lime" glass has a relatively high thermal coefficient of expansion.
The "Boru-silicate" glass features a thermal coefficient of expansion close to pure quartz. It's advantage over quartz is a MUCH lower melting point.
The original American Pyrex (r) was a Boru-silicate glass. Apparently, the owners of the trademark decided that in the US market they would use "tempered" soda-lime glass in place of the Boru-silicate glass.
The Tempered glass is good stuff. It's very, very break resistant and is moderately resistant to thermal shock. (It's actually created via a "thermal shock" process whereby the hot glass surface is suddenly cooled; another process uses a "case hardening" process when Potassium (K) replaces Sodium (Na). The potassium atom is a bit larger ad that places the surface under stress which has the same effect as quickly "tempering" the glass.
The neat thing about tempered glass is that when it does break it breaks into small pieces which are unlikely to cause a fatal injury. OTOH, true Pyrex (r) will, when broken, generate good sized slithers.
The types of lawsuits generated by broken tempered glass are as in the noise as compared to that generated by broken soda-lime glass.

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Watch out for broken tempered glass! While external to the vehicle, I had a front windshield shatter, in moving about the vehicle to retrieve items on the front seat, I gently brushed my back against the shattered widnshield. I did NOT even feel the small shards cut through my shirt and down into flesh until someone pointed out the blood running down my back. So yes, not fatal, but still as sharp as a scalpel.
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On Mon, 09 Jan 2012 08:32:38 -0800, Robert Macy wrote:

Is the windshield tempered?
I know the sides are (and they do break into little pieces - ask me how I know).
But the windshield is laminated I thought. Not tempered.
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On 1/9/2012 9:32 AM, Robert Macy wrote:

windshields aren't tempered.
i have buckets of chunks of tempered glass. i can run my hands through them without any cuts.
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Pyrex does not expand much when it is heated. I had two Pyrex one quart storage bowls (7201 05) that got stuck together. I put ice and salt in the inner one and put the outer one in very hot water. The temperature difference was at least 120 degrees Fahrenheit. The bowls were still stuck together. I did not see any change in relative size.
I have read (or seen on TV) that Russians often make tea in glass tumblers. They put a metal spoon in the glass to keep it from breaking. A silver spoon would conduct heat much better than a stainless steel spoon but stainless would probably be good enough.
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On 1/6/2012 8:27 PM, Chuck Banshee wrote:

As others point out, it is the thermal stress that breaks the glass. Pyrex type glass expands less and will take more stress but is too expensive to use for throwaway jars. The cheap jars if heated slowly and uniformly to minimize stress will take hot filling. In your case, adding the hot water slowly with swirling would probably be OK.
Also not a good idea to microwave items in this type glass.
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Owens-Corning sold the Pyrex brand name to a company that's now using it for soda-lime glass (not heat-resistant).
I once canned some peaches and didn't get the air bubbles out of the jars before putting them in the canner. The bottoms of the canning jars popped off very neatly, as though they'd been cut with a glass cutter.
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On 1/7/2012 8:23 PM, natp wrote:

You probably had the lids too tight to begin with...air is supposed to escape during the canning bath and then the lids seal as the jars cool. Should tighten before boiling so that the rubber seal barely touches, not tight. The rings, if separate, are then tightened after cooling. Test lid with a tap ..
The major issue with any kind of glass is even heating and cooling. One t'giving, getting the turkey ready, I moved an empty Pyrex pie plate onto a burner on our glass cook top. Sat down to dinner in the dining room and a couple of minutes later there was an explosion in the kitchen. The burner had been left on, and there were long shards of glass all over the kitchen. Don't want to know what it would have been like if one of us had still been in the kitchen.
Learned from glass crafting that various glasses have differing COE (coefficient of expansion, I think)...can put glass in a kiln to melt or fuse it, but two different glasses to be fused should have same COE or they cool at different rates and then crack. Took grandson to a glassblowing class...way cool. He had thought about being a glassblower but decided to make it just a hobby :o)
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On 1/8/2012 8:12 AM, Norminn wrote:

I did not see the Pyrex brand on my old canning jars and doubt that they were Pyrex.
Here's a Wiki link:
http://en.wikipedia.org/wiki/Pyrex
When I worked in a lab, all our glassware was Pyrex. I'd repair or modify things on occasion but the complicated stuff went to the labs professional glass blower. It was important to anneal the glass after modifying to remove stresses. Looking at glass with polarized lenses can show stress points.
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