The difference between PYREX (uppercase) and pyrex (lowercase) lies in the glass type: vintage/lab PYREX is borosilicate glass, resistant to thermal shock (freezer-to-oven safe); modern US pyrex is cheaper soda-lime glass, prone to shattering from sudden temperature changes, while European pyrex remains borosilicate. Look for all-caps PYREX for borosilicate (lab/vintage) and lowercase pyrex for soda-lime (modern kitchenware in US/Asia) to know if your dish can handle extreme heat shifts.
Last edited:
