And what country can preserve its liberties if their rulers are not warned from time to time that their people preserve the spirit of resistance? Let them take arms. The remedy is to set them right as to facts, pardon and pacify them. What signify a few lives lost in a century or two? The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants.
Sunday, August 25, 2024
We still have Pyrex bowls that are who knows how old.
Microwave safe before there was Microwaves. Hot glass shatters with just a little bit of cool water don't rinse or even set it in a mostly dry sink until it has completely cooled. Sciences not a flaw
Originally, Pyrex was made with thick borosilicate glass. This glass has a lot more heat resistance, but costs more. The breakage was controlled by making it thick. The result was long-lasting cookware, with a bit of care. Then the Pyrex brand was bought by a Chinese company. Modern Pyrex is a thick soda glass. This is far inferior in terms of heat resistance and breaks easily. But it's cheap. You can still buy some borosilicate Pyrex, for about 3 times the price as the soda glass. If your Pyrex has a green tint it is the cheap stuff. Borosilicate glass is clear.
Absolutely right. Borosilicate has a much lower coefficient of expansion - why it's used for lab ware - than soda glass. The newer stuff is case-hardened (sort of) by replacing some of the surface sodium atoms with bigger potassium, which produces a stressed outer surface (like Prince Rupert's Drops). Resists an impact until it doesn't, at which point it literally explodes. And scratches (think age) make it more likely to explode. Incidentally: easy way to spot borosilicate glass. It has an index of refraction nearly identical to glycerin, so if immersed in glycerin it will near-as-dammit disappear. Soda glass is still easily seen. The green tint is indeed a tip-off, but it's not an inherent property of good quality soda glass (which is also clear). It's just that the Chinese use scrap glass cullet in the melt and aren't picky about it.
Cooking with pyrex is a risk. The explosive shattering effect is dramatic.
ReplyDeleteThermal fatigue. Sooner or later.
DeleteThe newer ones are garbage, the older ones from the 50,60,70s are good.
DeleteWhen the pan is cold, putting it over intense heat will cause "Thermal Shock."
DeleteSame for hot pan introduced to cold water.
As a department store cookware buyer for many years, we had several reports by customers of their Pyrex and/or Corning Ware exploding.
Microwave safe before there was Microwaves. Hot glass shatters with just a little bit of cool water don't rinse or even set it in a mostly dry sink until it has completely cooled. Sciences not a flaw
ReplyDeleteooh,ooh, show one exploding !
ReplyDeleteI don't cook with the Pyrex stuff but they do go well with the vintage Fireking measuring pitchers & Fiestaware.
ReplyDeleteI have quite a few Pyrex and other glass cookware items that I use often ... but only in the microwave.
ReplyDeleteOriginally, Pyrex was made with thick borosilicate glass. This glass has a lot more heat resistance, but costs more. The breakage was controlled by making it thick. The result was long-lasting cookware, with a bit of care. Then the Pyrex brand was bought by a Chinese company. Modern Pyrex is a thick soda glass. This is far inferior in terms of heat resistance and breaks easily. But it's cheap. You can still buy some borosilicate Pyrex, for about 3 times the price as the soda glass. If your Pyrex has a green tint it is the cheap stuff. Borosilicate glass is clear.
ReplyDeleteAbsolutely right. Borosilicate has a much lower coefficient of expansion - why it's used for lab ware - than soda glass. The newer stuff is case-hardened (sort of) by replacing some of the surface sodium atoms with bigger potassium, which produces a stressed outer surface (like Prince Rupert's Drops). Resists an impact until it doesn't, at which point it literally explodes. And scratches (think age) make it more likely to explode. Incidentally: easy way to spot borosilicate glass. It has an index of refraction nearly identical to glycerin, so if immersed in glycerin it will near-as-dammit disappear. Soda glass is still easily seen. The green tint is indeed a tip-off, but it's not an inherent property of good quality soda glass (which is also clear). It's just that the Chinese use scrap glass cullet in the melt and aren't picky about it.
Delete