Pyrex – the brand that 75% have in our cupboards – the tempered glass cookware that we use to cook and tote baked beans, casseroles, and sweet potatoes to Thanksgiving dinners, Super Bowl parties, and to our dining room tables – is, indeed, made in Charleroi, Pennsylvania.
Pyrex is a Corning product that was originally developed as a lantern glass for railroad signals. The signals were subjected to intense heat and would often break when hit with rain or snow. Pyrex is a “low expansion” glass made from silica and a smattering of other materials. It is cooked at over 3000 degrees to mold a extremely heat resistant product that is exceptionally durable. It has the extraordinary characteristic of absorbing heat rather than reflecting heat – which, regular glass, porcelains and enamels tend to do. Pyrex is also see through (as we know)- allowing bakers to easily check when their dish is finished by gazing through the bottom.
As legend has it – Pyrex became a consumer produt after a wife of a Corning employee implored her husband to bring home some of the material that his company had developed – she had heard about its resistance to heat and its durability. What she discovered was that the “cookware” had some astounding properties – it was incredibly durable, food cooked eveningly within the dishes and in less time, and it was naturally “non-stick”. The husband and wife pair took the idea to the product designers and Corning cookware was born. It took years to persuade kitchen goers that glass was a suitable cookware – but, eventually the product would become one of the most widely used and recognized brand names in American kitchens.
Pyrex is distributed worldwide and has always been manufactured in Pennsylvania. They do import some of their plastic coverings and other metal products, such as their Grip-Rite products – but the rest originates in Charleroi.