Vintage Pyrex can go straight from freezer to oven, while modern Pyrex must be brought at least to refrigerator temperature beforehand. Vintage Pyrex can also handle the rising, shifting temperature of a preheating oven, while modern Pyrex glass should only go into a stable, preheated oven.
New Pyrex is better at handling physical bumps and bangs (drops, banging into the counter, etc). Old Pyrex is better at handling temperature shock (setting onto wet counter, taking out of freezer and putting directly into preheated oven, etc).
If it's all caps “PYREX,” it's vintage, made of borosilicate. If it's lower case “pyrex,” it's new, and it's soda lime. (In Europe, Pyrex is still made of borosilicate. So these recommendations only apply to Pyrex in the United States.)
The brand switched its formula in the 1950s to the soda lime glass, but recently started reintroducing borosilicate glass. Although both glasses are heat-resistant, borosilicate glass does better with extreme temperatures, making the vintage Pyrex pieces highly coveted by collectors.
Pyrex bowls (both old and new) are safe to use in your oven -- and microwave -- as long as you avoid dramatic, sudden temperature changes. Stovetop (either gas or electric) use is not safe.
Broken or chipped Pyrex should be disposed of carefully in the waste bin.
What Makes Pyrex Special. "Pyrex continues to hold its value because most of us associate it with memories of family and holiday gatherings and memories from their childhood," Wright says. "The vintage designs and patterns of Pyrex evoke a nostalgia, which adds to its value for collectors.
Corning divested itself of the Corning Consumer Products Company (now known as Corelle Brands) in 1998 and production of consumer Pyrex products went with it. Its previous licensing of the name to Newell Cookware Europe remained in effect.
FYI: Don't put your vintage Pyrex in the dishwasher; its shiny finish will be destroyed. DWD is hard to rehab, although you can rub some coconut oil on a piece to simulate its former sheen. Other damage may look bad, but is actually quite reversible.
Decorative patterns are also key to determining the glassware's value. Lucky in Love, a sweet pink and green design, is prized for its rarity and promotional production. Wright notes that Amish Butterprint, Pink Gooseberry, Snowflake Blue, Crazy Daisy and Friendship are also considered valuable in the Pyrex community.
Patterned Pyrex—such as the 1956 Pink Daisy or the 1983 Colonial Mist colorways—tend to be valuable as a collector's item. Other popular patterns include the 1957 Butterprint, which features an Amish couple and their crops, and has been valued at a few hundred dollars.
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.
Allow Pyrex to Come to Room Temperature Before Changing Its Temperature. This goes for transferring Pyrex from the fridge or freezer to the oven, or vice versa. Allow Pyrex to come to room temperature before immersing in water or placing in the freezer, refrigerator, microwave or pre-heated oven.
The Bottom Line
pyrex: Lowercase indication of containers that should not be heated in the oven or microwave. These are most likely made of soda-lime glass. PYREX: Uppercase label on cookware that is made of borosilicate glass and can be heated in a microwave or oven.
there is no differance in anchor or pyrex they are exactly the same glass soda lime glass.
As long as you follow the same guidelines above, vintage Pyrex is A-OK to go in the oven and can be used in oven temperatures up to 425ºF (and skip the broiler).
For people worried about making food in plastic containers, glass Pyrex is relatively clean and the vintage pieces are American made. (The modern ones are, too.) And while they're old, they're also surprisingly durable. "I tend to have a heavy hand in the kitchen," Mancha says.
Along with Butterprint, Gooseberry was one of the first patterns debuted on the new “Cinderella Bowls.” Cinderella Bowls were a series of large nested mixing bowls with a handle or spout on each side, which were designed by John Philip Johnson.
So, why did Pyrex make the change all those years ago? Two primary causes: increased air pollution regulations and a focus on reducing energy consumption. Soda lime glass is better for the environment, requires less energy to produce, and is more easily recyclable—making it the preferable choice.
Here's where the branding comes in. All-caps PYREX, which is sold and made in France, is still made of borosilicate glass. But any Pyrex that's all lowercase — a recent change in branding — is soda-lime glass, which isn't designed to withstand drastic temperature changes.
The best way is to look at the bottom of the product. My vintage Pyrex, which is at least 40 years old, and definitely boro-silicate, reads “Not For Lab Or Stovetop Use - Corning N.Y. - U.S.A. - 516 - PYREX.” Newer products made of soda-lime glass do not read Corning N.Y., nor are they made by Corning.
“The most rare Pyrex patterns are the promotional Pyrex,” says Lucie Courchesne of LucysMidCentury. Promotional Pyrex patterns were sometimes referred to as “non-standard” and were usually offered for a limited time. The company often marketed them as gifts for holidays.
in early 2022, sales of Pyroceram-based CorningWare were temporarily discontinued in the USA but reappeared on the market in early 2023. It continues to be sold in other regions of the world.
Vintage Pyrex has fans for practical reasons: It's tougher than modern Pyrex. All Pyrex cookware, old and new, is made from tempered glass, which stands up well to high and low temperatures.