Pyrex is a popular brand of cookware that has been a staple in kitchens for decades. It was first introduced in 1915 and has since become a household name.

While Pyrex is known for its durability, there are some precautions you should take when using old Pyrex to ensure your safety.

What is Pyrex?

Pyrex is a type of glass that was developed by Corning Glass Works in the early 1900s. It is made by adding boron to the glass mixture, which makes it more heat-resistant and shatterproof than regular glass.

Pyrex is used for a variety of products, including baking dishes, measuring cups, and mixing bowls.

What Makes Old Pyrex Different?

Old Pyrex is different from newer Pyrex because it was made using a different process. The older Pyrex was made of tempered soda-lime glass, which was not as resistant to thermal shock as borosilicate glass.

This means that old Pyrex is more likely to break or shatter when exposed to extreme temperature changes.

How to Tell If Your Pyrex is Old

If you have inherited Pyrex from a family member or purchased it second-hand, it can be difficult to tell if it is old or new. One way to tell is by the color of the glass.

Old Pyrex is often a milky white or opaque color, while newer Pyrex is transparent. Another way to tell is by the stamp on the bottom of the dish. Old Pyrex is often stamped with “Pyrex Made in the USA,” while newer Pyrex may have a different stamp.

Precautions to Take When Using Old Pyrex

When using old Pyrex, it is important to take some precautions to ensure your safety. Here are some things to keep in mind:.

1. Avoid Extreme Temperature Changes

Old Pyrex is more susceptible to thermal shock, which can cause it to break or shatter when exposed to extreme temperature changes. Avoid going from hot to cold or vice versa, and never put an old Pyrex dish in the freezer or on a hot stove top.

2. Check for Cracks or Chips

Before using an old Pyrex dish, inspect it for cracks or chips. Any damage to the dish can compromise its integrity and lead to breakage. If you notice any damage, don’t use the dish.

3. Use in a Preheated Oven

When using an old Pyrex dish in the oven, it is important to preheat the oven first. This can help prevent thermal shock by gradually raising the temperature of the dish.

4. Use Oven Mitts

Old Pyrex can get hot in the oven, so it is important to use oven mitts or a towel when handling hot dishes.

5. Avoid Sudden Temperature Changes

When taking an old Pyrex dish out of the oven, place it on a dry, heat-resistant surface. Avoid setting it on a cold countertop or in a sink filled with water, as this can cause thermal shock.