You are probably looking at a glass baking dish with Pyrex printed on the bottom and another one with PYREX in bold uppercase letters. Now you may be thinking, Are these two different? Is one safer than the other? Am I going to blow up my lasagna?
I have seen the panic. I have read the many online posts. And yes, the difference between them does exist. However, it is not as scary as many parts of the internet want you to believe.
The reason there is a difference between Pyrex and PYREX lies in the type of glass that is being used and where the glass was manufactured, not just the logo.
Let us break down what you need to know.
What Is Pyrex with a Lowercase P
If you have purchased any glass baking dishes, glass measuring cups, or similar items in the United States over the last several decades, chances are you have Pyrex with a lowercase p. This type of Pyrex is made from tempered soda-lime glass. Tempered glass is selected for its strength and impact resistance.
Plainly speaking, it will survive drops much better than its predecessor. I have personally dropped mine on the kitchen counter, and it bounced back, although I would not recommend trying that.
Soda-lime glass, however, is not as tolerant of rapid changes in temperature. For example, pouring boiling water into a cold glass dish or taking a dish directly from the freezer to the oven could create problems. You could literally burn yourself. Nonetheless, if used correctly, without extreme temperature shocks, it is perfectly safe to use for common household cooking tasks.
What Is PYREX with Uppercase Letters
){kind=link}