The short answer is yes, you can absolutely put Pyrex glassware in the freezer. However, there are some tips and precautions to follow when freezing Pyrex to avoid cracking or shattering.
In this post, we’ll explore the reasons Pyrex is freezer-safe, how to properly freeze Pyrex, what types of Pyrex can go in the freezer, and answer some frequently asked questions.
What Makes Pyrex Glass freezers Safe?
Pyrex glassware is designed to be thermal shock-resistant, meaning it can withstand sudden temperature changes without cracking or breaking. Here are the key factors that make Pyrex freezer safe:
- Borosilicate glass – Pyrex is made of borosilicate glass, which has very low thermal expansion. This means the glass doesn’t expand or contract much when temperatures change rapidly.
- Tempered design – Pyrex glass bakeware and containers go through a tempering process to put the glass under controlled stress. This makes it more resistant to thermal shock.
- Thick walls – Pyrex products are designed with thicker glass walls than typical glassware. The extra thickness provides strength and durability.
So in summary, Pyrex’s unique glass composition and design allow it to withstand freezing temperatures without cracking or shattering.
Proper Technique for Freezing Pyrex
While Pyrex is freezer-safe, there are some best practices you should follow when putting it in the freezer:
Allow the food to cool first.
Don’t put hot foods or liquids directly into the refrigerator or freezer in glassware. Allow cooked foods to cool to room temperature first. This prevents excessive temperature changes that could lead to cracking.
Avoid putting empty Pyrex in the freezer.
Only freeze Pyrex containers when they contain food or liquid. The contents help regulate temperature changes. Sudden temperature drops can shock and weaken empty Pyrex.
Don’t freeze shelf-stable Pyrex.
Some Pyrex products, like cups or mixing bowls, are designed for shelf-stable storage, not freezing. Only freeze Pyrex marketed as oven-safe or freezer-safe.
Allow for expansion.
Liquids expand as they freeze, so don’t fill containers to the brim. Leave at least 1/2 inch of headspace for expansion.
Increase freezer time for large pieces.
Give the freezer extra time to fully chill very large Pyrex casserole dishes or bowls before touching or moving them.
Following these tips will help prevent thermal shock and make Pyrex glassware last through many freeze/thaw cycles.
What Types of Pyrex Can Go in the Freezer?
As a general rule, any Pyrex labeled oven or freezer safe can withstand freezing temperatures. Some examples of Pyrex products suitable for the freezer include:
- Pyrex freezer, fridge, and oven containers
- Pyrex glass baking dishes and casserole dishes
- Pyrex mixing bowls
- Pyrex plastic container lids
- Pyrex True Snapware plastic containers
- Pyrex Smart Essentials glass food storage containers
On the other hand, some Pyrex is not well-suited to freezing:
- Pyrex primary-colored mixing bowls: these lack the thermal shock resistance needed for freezing.
- Pyrex prepware: this plain glass bakeware is only oven safe, not freezer-safe.
When in doubt, check the product description for keywords like “freezer safe” or “thermal shock resistant”. Or look for the snowflake symbol on Pyrex that indicates it’s freezer safe.
Handling Pyrex from the Freezer
Once your Pyrex containers are frozen, here are some tips for thawing and handling them to avoid damaging them:
- Thaw in the refrigerator – Don’t thaw glassware at room temperature or in the microwave. Slow thawing in the fridge prevents thermal shock.
- No stovetop thawing – Don’t put frozen Pyrex directly on the stovetop or use it for cooking while frozen. Only thaw in the refrigerator.
- Handle with care – Use dry oven mitts and grasp firmly from underneath when removing from the freezer. Sudden temperature changes can make glass brittle.
- Avoid severe temperature changes – Don’t add very hot ingredients to frozen Pyrex, run frozen containers under hot water, or expose glassware to other extreme temperature swings.
- Separate when storing – Wrap containers in towels or use dividers to prevent frozen glassware from clanking together in the freezer. This avoids weakening the glass.
Following this careful handling process will keep your Pyrex intact through many freezer sessions.
Frequently Asked Questions About Freezing Pyrex
Can all Pyrex go in the freezer?
No, not all types of Pyrex are freezer-safe. In general, Pyrex, marketed as oven- or freezer-safe, is designed to withstand freezing temperatures without cracking. Products like primary-colored mixing bowls lack that thermal shock resistance.
Does Pyrex break in the freezer?
Pyrex should not break in the freezer if used properly. However, sudden temperature changes, overfilling containers, or improper handling can potentially cause cracking or shattering. Follow the tips above to prevent damage.
Can you put hot Pyrex in the freezer?
No, don’t put boiling hot Pyrex straight into the freezer. Always allow cooked foods to fully cool down first to avoid thermal shock from severe temperature swings. Letting food cool prevents the glass from expanding and contracting too quickly.
Is plastic or glass Pyrex better for the freezer?
Both Pyrex plastic containers and Pyrex glass containers can safely go in the freezer. The plastic may hold up better to abrasion or drops in the long term. But glass won’t absorb stains or odors like plastic can over time.
Can Pyrex leak in the freezer?
When used properly, Pyrex is leak-proof in the freezer. However, repeated freezing can wear down plastic lids and gaskets over time, potentially allowing leaks. Inspect containers occasionally and replace components that become warped or damaged.
Following the guidance in this post will allow you to safely freeze a variety of Pyrex products. Always be sure to use proper technique and handle frozen Pyrex carefully. With some basic precautions, Pyrex glass and plasticware can provide convenient, durable freezer storage.
Hi, I’m Julie, the passionate foodie and founder of Juliesfamilykitchen.com. I created this blog out of a drive to prove someone wrong, and then I realized how much I truly enjoy cooking and trying new recipes. In my free time, when I’m not running around after my kids or spending quality time with my partner, you can usually find me in the kitchen experimenting with new dishes.