Pyrex has become a kitchen favorite because of its versatility. The same dish can be used to mix ingredients, bake casseroles, store leftovers, and reheat meals, making it a convenient all-in-one solution. However, despite its reputation for durability, Pyrex is still made of glass and has limits that every cook should understand.

The biggest risk is thermal shock, which occurs when glass experiences a sudden, extreme temperature change. For example, placing a refrigerator-cold Pyrex dish directly into a hot 425°F (220°C) oven can create uneven stress within the glass, increasing the chance that it will crack or shatter. To reduce this risk, allow chilled dishes to sit at room temperature for a while before baking, or place them in a cold oven and let both the dish and oven warm up together.

Moving a Pyrex dish directly from the freezer to a hot oven is even riskier. Whether it’s older borosilicate glass or the tempered soda-lime glass commonly used in many newer Pyrex products, no glass is completely immune to rapid temperature changes. Frozen meals should be thawed first whenever possible or transferred to another suitable baking pan before cooking.

It is also wise to avoid placing hot Pyrex on cold or wet surfaces, adding cold liquid to a hot dish, or exposing it to sudden changes in temperature. These situations can also create thermal stress that weakens the glass.

With proper care, Pyrex can last for decades. The key is to treat it as durable glass rather than an unbreakable product. By respecting its temperature limits and avoiding sudden changes, you can continue using your Pyrex safely for baking, cooking, storing, and reheating meals for many years.