What's Actually Happening With Pyrex
Pyrex is not out of business. The brand is still very much active, though the company that makes it and the formula behind the glass have changed over the decades. That confusion is probably where this myth comes from. In 1987, Corning Inc. sold its Pyrex cookware division to World Kitchen, which later became Corelle Brands. The glass formulation also shifted. Older Pyrex was made from borosilicate glass, the same dense, heat-resistant material used in lab beakers. The newer US-made Pyrex switched to soda-lime glass, which is cheaper to produce but more prone to thermal shock. People who noticed their modern Pyrex breaking under high heat assumed the brand had disappeared or been replaced by a fake. It wasn't a shutdown. It was a materials change paired with a corporate sell-off. I've had people message me saying their Pyrex dish shattered in the oven at 425 degrees. The first thing I ask is whether it's the old heavy glass with the rounded lip or the newer lighter version. In nearly every case, the dish is the post-1980s soda-lime type, and someone put a cold dish straight into a hot oven or ran it through a thermal cycle it wasn't designed to handle. Soda-lime Pyrex can still go in the oven. It just has a narrower safe temperature range than borosilicate did.
If you want the original heat-resistant version, look for vintage Pyrex labeled "Corning Ware" from before 1987, or check if your current piece says "borosilicate" anywhere on the packaging or bottom stamp. Some brands like Duralex in France still make borosilicate bakeware that performs closer to the old standard. Wolseley, the current licensee, also produces borosilicate lines under the Pyrex name in certain markets, but the product mix varies by region and retailer. The "Pyrex Out Of Business" rumor also gets boosted every time someone posts a video of a dish cracking and overlays it with sensational text. The algorithm does the rest. The reality is quieter: the brand rebranded, reformulated, and kept selling. If you're dealing with cracked dishes or suspicious failures, the fix isn't a workaround or a replacement tool. It's understanding which material you're actually using and adjusting your thermal habits accordingly.
