Why All Pyrex Is Not Created Equal: The History of Ordinary Things
The critical issue for glass is the ability to adjust to temperature changes. Glass expands at different rates resulting in tension, cracks, and shattering. Three types of glassware are typically found in American kitchens:
- Soda-lime glass, used for most drinkware from juice cups to jars, is more susceptible to breaking with temperature changes.
- Tempered glass is soda-lime glass that’s been heat-treated making it more durable.
- Borosilicate glass contains boron trioxide, the element that makes glass resistant to temperature changes. For example, it doesn’t break when taking a dish from a refrigerator to an oven. Pyrex is a sub-group of borosilicate glass.
In 1893, a German chemist . . .