Did You Know – PYREX vs pyrex
Do you know there are two logos for Pyrex and do you know what the difference is between them? PYREX or pyrex, which is safer and what’s in your kitchen?
There are three different types of glassware typically found in kitchens? They are soda-lime, tempered and borosilicate.
Borosilicate glass includes boron trioxide, which has a low thermal expansion. Unlike normal glass, it won’t break when exposed to major temperature shifts such as taking a dish from a fridge to an oven. This is thanks to boron trioxide, the element that makes glass resistant to major temperature changes. Pyrex is a sub-group of borosilicate.
Soda-lime glass is the most common glass type in kitchens since it’s used for most drinkware from juice cups to jars. Untreated soda-lime glass is more susceptible to breaking from extreme temperature changes. This shock expands the glass at different rates, resulting in cracks and fissures.
Tempered glass is just soda-lime glass that’s been heat-treated to make it more durable. During that heat-tempering process, the exterior of the glass is force-cooled so that it solidifies quickly, leaving the center to cool more slowly. As the inside cools, it pulls at the stiff, compressed outer layer, which puts the center of the glass in tension.
Are “PYREX” and “pyrex” the Same?
Both trademarks were historically used interchangeably in the marketing of kitchenware products made up of both borosilicate and soda-lime glass.
However, now Corning has licensed out the use of their PYREX (upper case lettering) and pyrex (lower case lettering) logos to other companies.
Lowercase pyrex is now mostly used for kitchenware sold in the United States, South America, and Asia. In Europe, Africa, and the Middle East, uppercase PYREX is still available.
Pyrex used to be made of the more heat-resistant borosilicate glass, which is more resistant to breakage when subjected to extreme shifts in temperature.
Pyrex eventually switched to tempered glass most likely because boron is toxic and expensive to dispose of. Although tempered glass can better withstand thermal shock than regular soda-lime glass can, it’s not as resilient as borosilicate.
If the logo is in upper case lettering, PYREX, it’s most likely made of borosilicate, and thus safer. The lowercase lettering is most likely made of soda-lime glass, so take extra care after any high-heat cooking. Most glassware products will include warnings so make sure to read about proper handling, cleaning, and storage.
All of my measuring cups are pyrex, like my picture above. I have boiled water in them in the microwave with no problem except once when the bottom broke right off, I am proof lowercase pyrex do break. If you ever had a casserole dish prepared ahead of time (you have it in the refrigerator) and the recipe states to take it out for 15 minutes before baking, make sure you do or the extreme cold to hot can shatter that dish as well. Losing the dish is bad but ruining your dinner is not acceptable!
SOURCE: http://www.AllRecipes.com
http://www.InDianesKitchen.com
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Categories: Cooking Tips, Did You Know
Good article!
Thank you!
I will buy PYREX! Sounds like a safer bet for someone is who is an amateur cook.
I was shocked all mine are pyrex, but that is what the article said is sold in the USA.
I never knew there were two types, or logos of pyrex. I’ve still got my late mum’d old pyrex jug, like you’ve pictured here, and she’d had that for years. I use it all the time, it’s so handy. I’ve got a couple of dishes as well.
I have a lot of measuring cups and they do last forever. That’s sweet you still have your mom’s.
never knew about this.
One of those facts the company doesn’t say much about.
Oh my goodness – I thought they were the same thing! Thanks for the info 🙂
You’re welcome!
Good to know. I was wondering why the lettering on my one-cup measure was fading away to nothing.
I’m going to be paranoid now when I use mine in the microwave to melt butter. I also boil my hummingbird food in my large one, I hope it doesn’t ever break. But then again, anything we use could have the same effect.
You could have given a million years anda million dollars, I never would have guessed this one! Good information though. Nice one Goddess.
I learned about it when my measuring cup broke in two years ago. They said some casserole dishes have exploded too.
Oh dear!
had no idea
I had read about this many years ago then my husband saw something about it on line and reminded me. I found it interesting.
I had no idea about the three different kinds of glass. Good info. I ran to my kitchen and found that one was “pyrex” and the other two were Anchor Hocking. I guess that will send me down another rabbit hole.😉
Hahaha It is really bothering me because mine are all pyrex and I melt butter in them all the time. But I guess all the dishes I put in the microwave could break the same way. It was so much easier when we didn’t know right? 🤣
I didn’t know about this until a few months ago when I was shopping for new measuring cups.
I love mine and always thought they were top of the line.
Thanks. I had heard Pyrex was now un-trustworthy. Tha KS for telling me what to look for.
Esthetic PYREX all capitals a health risk with the boron in it
You’re welcome Katelon. FYI the boron is tightly bound within the glass structure and does not leach out into food or drinks. They said it is completely safe. Glass is the safest material to use for food.
Very interesting!
I thought so too. All mine are pyrex.
😂🙏🏻❤❤A good article about Pyrex. I have tried most of its types. It is beautiful and economical. It is possible to cook and serve on the table, and this is very beautiful. Good luck, happiness and success, my love.
Thank you, I too am a lover of Pyrex!
🙋🏻♀️🌹🌹🙏🏻
Thank you!
I didn’t know that Diane and just assumed the two names were used interchangeably!
I never even noticed there were 2 ways they spelled it, with upper and lower case, until mine broke in the microwave and I looked into it.
More people should know this … thank goodness you were not burned!
Luckily it broke in the microwave.
Yes! I wanted a microwave after we got one at work and I’d take leftovers to work and heat them up. I told my mom it would make her life easier for heating up leftovers especially and you’ll love this … she liked bacon but not the mess, so we made it in a covered dish in the microwave. Anyway, I got it and she read the booklet and said “take it back – it has too many warnings!” I said “we’ll be careful.” A friend of the family’s son lived a few doors away from us. He lived alone and bought a microwave. He put a dish in the microwave with a gold rim on it … yes, a no-no. We bought the Corelle microwave plates before using the microwave the first time. The metal on the dish rim blew the microwave door off and did damage in the kitchen. He was lucky it didn’t hit him as he was standing nearby waiting for dinner!
Oh my gosh! When I was young and stupid, I but a plate from my good china in and it has silver around the edge. It sparked like crazy but luckily I was right there and shut the microwave off. It didn’t damage the microwave or my plate thank God.
Yes, Jim was lucky he wasn’t injured as I’m sure the door, if it hit him, would be a powerful blow. After we got the microwave, I used an egg cooker in the microwave to make hard-boiled eggs. It was a plastic egg-shaped device and you filled it with water and it had four metal indentations to sit the eggs in. We used it for years and once I did not have the lid on tight and when I went downstairs to get the eggs, there was egg splattered everywhere inside the microwave! No damage to the microwave, but the lid must have just been slightly off because I would have noticed it otherwise.
Oh my gosh! Good thing the door was closed but what really surprises me is you said it had metal indentations. I had always read never put metal in the microwave.
Yes, they tell you that in the manual. Maybe because the metal portion was inside the plastic egg-shaped cooker. But the lid didn’t twist shut, at least ours didn’t. You just put it on top of the bottom portion. It made a heck of a mess though!
I always wondered about those Chef Boyardee microwave single serve containers because they have a metal rim around the container at the top, however, you put the plastic lid over it when it cooks. I bet that was a mess and it seems that all gadgets are a pain to clean.
Gee I never thought about that. I remember I always had some of those at work and the Chunky Soup too in case I forgot my lunch, or worse yet, had to spend the night at work. Once, many years ago, the Firm let us go at 3:00 p.m. as it was blizzard-like conditions. It was long before cellphones – called my mom from work and said we were getting out early and I’d catch the first bus home. I finally got a bus very late, it didn’t go to my city, but someone I knew from high school was at the bus stop and she said “get on my bus, I’ll call my dad and he can pick both of us up and take you home” … she walked to the bus stop usually, but it was too far to walk in the heavy snow. Got home at 10:00 p.m.!!
Oh my gosh Linda! I bet your mom was worried sick! That was nice of your friend and her dad.
Yes she was Diane and this was long before cellphones. We went a different route home as she lived in another city, but we all queued up at the same area to take the bus. We got off in front of a bar on a busy street corner and we went in to call him and it was snowing like crazy so we knew he’d be awhile. I finally called my mom at about 9:00 and said I’ll be home eventually. So this was a coney island place and so I go coneys for us to eat and some for home and for her dad. I remember thinking that in a few more hours I’ll be getting up to go back to work again. They did not shut the office down, so after that I had a change of clothes, some food in my desk drawer, etc. … never would I go through that again. We had so many people on the bus, more than was allowed, that’s for sure and slipping and sliding. There were a few long bus rides in/out to Downtown Detroit in my day … when I had the opportunity to work from home eventually, I was happy to grab it.
Diane – I just looked for this product and it’s still available from Nordicware and the insert is aluminum … I think ours was Nordicware. I never used it again after this incident though.
https://www.nordicware.com/products/egg-boiler/?srsltid=AfmBOopZJSTIXdNOvFY6QlOJ7gIEwgCR7llWIBAkJegPK5icHk6H64pu
Interesting Linda, I don’t ever remember seeing them, how strange it has metal.
It did work well Diane and I read the reviews and all but one person gave good reviews and some people were on their 2nd or 3rd one already or had given some as gifts. Totally metal inside the egg – hmm.
Now I’m going to go check my pyrex/PYREX and see what I have!
That’s what I did too!
I’m going to have to look at my Pyrex kitchenware now to see if they’re upper case or lowercase. What an interesting detail I would never have even thought twice about until your post!
Haha that was the first thing I did too!
This was really informative. Now, I have to take a moment and look at my Pyrex measuring cups. Interesting too, pyrex is also used generically to refer to glass measuring and/or baking dishes.
Thanks for sharing.
I haven’t looked at my baking dishes yet. I only have a few but all my measuring cups are pyrex. You’re welcome!