Can You Freeze Glass Storage Containers? Here's How to Do It Safely

Key Takeaways

• Glass containers are freezer-safe only if they’re made of tempered glass, as regular annealed glass can crack or shatter under thermal shock.
• Safe freezing starts with proper technique: cool food first, leave headspace for expansion, avoid overfilling, and seal containers tightly.
• Tempered glass can stay in the freezer indefinitely, but food quality depends on storage time, airtight seals, and stable freezer temperatures.
• Gradual thawing is essential. Always thaw in the refrigerator or at room temperature, and avoid sudden temperature changes to prevent thermal shock.

Cooks are right to worry about glass containers shattering in the freezer. Not all glass is freezer-ready, and rapid temperature changes can cause cracking.

You can freeze glass containers, but only if they're made from tempered, freezer-safe glass. This guide covers how to identify safe containers, use proper freezing techniques, and thaw properly.

Can You Freeze Glass Storage Containers?

Yes, but only tempered glass designed for temperature extremes. Non-tempered glass is susceptible to thermal shock, which is rapid temperature changes that cause it to expand and contract unevenly, leading to cracks.

Cooks need to identify freezer-safe containers. You can look for freezer-safe symbols (typically a snowflake) or check the manufacturer’s guidelines to confirm that the product is tempered glass.

Regular glassware you typically use for dry storage, such as mason jars, may shatter if not freezer-rated.

Why Tempered Glass Matters for Freezing

Freezing puts glass under significant stress. As temperatures drop, glass contracts, and if that contraction happens unevenly, cracks and breakage quickly follow. That’s why the type of glass you use matters.

Tempered glass is designed to handle temperature extremes. It’s heat-treated to over 1,000°F and then rapidly cooled. This process creates internal tension and surface compression. Those opposing forces make tempered glass about four times stronger than regular glass and far more resistant to thermal shock.

Standard glass, also called annealed glass, cools and contracts unevenly because of its weaker molecular structure. Annealed glass can't withstand the expansion caused by freezing liquids. 

However, annealed glass is great for handling the high pressure and heat of canning and storing hot foods. That’s why mason jars are typically made of thick, annealed glass. 

If you store these jars in the freezer, they may develop stress fractures, spiderweb cracks, or shatter completely. 

How to Safely Freeze Food in Glass Containers

Follow these steps to safely freeze food in glass containers. 

1. Leave Headspace: Water content in foods expands when it is frozen. Foods with more water, meaning liquids, need more headspace. Give 1 to 2 inches for liquids and ½ inch for solids.
2. Cool Food First: Let hot food reach room temperature before freezing. This prevents sudden temperature shock and improves food texture. You can let the food cool in the class container before freezing. 
3. Label the Container: Use masking tape and a marker to label the container with the food item and the date. This ensures you defrost and consume the food within its safe-to-eat date. 
4. Avoid Overfilling: Remember, even solid foods need a little room for expansion. If you overfill the container, you risk the lid popping off. 
5. Place Containers Upright When Freezing: You do not want your frozen food to stick to the container lid. Make sure your glassware is upright on a flat portion of the freezer. 

Some chefs first freeze uncovered to allow room for expansion and expedite freezing, then seal the container once the food is frozen through. If you’re using freeze-safe glass and leaving headspace, this step is unnecessary. 

How Long Can Glass Containers Stay in the Freezer?

Tempered glass is indefinitely freezer-safe, and there’s no degradation over time. How long your container should stay in the freezer depends on what’s in it. Some foods do not freeze well and should never be frozen, such as custard, homemade eggnog, salads, and hard-boiled eggs. 

Otherwise, these are the recommended best-by timelines for the most popular home-frozen foods. 

• Cooked leftovers (meat-based): 2-6 months
• Fatty fish (salmon, tuna, mackerel): 2-3 months
• Lean fish (cod, halibut, flounder): 6-8 months
• Whole chicken or turkey: Up to 1 year
• Poultry pieces: 9 months
• Ground meat (beef, turkey, chicken, pork): 3-4 months
• Steaks, chops, roasts (beef, pork, lamb, veal): 6-12 months

The best way to prevent freezer burn is to seal your containers tightly and minimize temperature fluctuations. This means you need to avoid repeatedly opening your freezer. Remember to always label and date containers to help with rotation and prevent waste.

The Right Way to Thaw Frozen Glass Containers

First, never run hot water over frozen glass, microwave containers with metal lids attached, or place frozen glass directly on the stovetop. These sudden temperature jumps are the most common cause of breakage. 

Gradual thawing is always the best method. Reverse thermal shock is just as dangerous as freezing too fast. Glass needs time to adjust as temperatures rise.

For best results, thaw completely, then transfer food to appropriate cookware before reheating. Here are your thawing options:

• Refrigerator Method (Safest): Remove the container from the freezer and place it in the fridge; let it thaw overnight. This slow, controlled temperature change preserves food texture and minimizes the risk of thermal shock.
• Room-temperature Method: Place the container on the counter and allow it to thaw gradually. Depending on the portion size, this usually takes 2 to 3 hours and is still gentle enough for freezer-safe glass.

Troubleshooting Common Glass Freezer Problems

It’s normal to encounter occasional issues when freezing with class containers. Use this advice to make the process a lot easier. 

• Lids Won't Come Off: A vacuum seal may form during freezing. Run warm (not hot) water over the lid only to release pressure.
• Condensation Inside Container: This is normal if the seal is good, but check for cracks if excessive moisture appears.
• Cloudy Glass After Freezing: Usually mineral deposits from water, not cracks. Wash with vinegar to clear it out.
• Container Cracked: Overfilled containers are prone to cracking. The good news is that, unlike regular glass, tempered glass does not break into sharp shards; it crumbles into small, rounded pieces. Use safety gloves, a brush, and newspaper to wrap the container and dispose of it. 

Freeze Glass Containers with Confidence

Whether you're storing batch-cooked meals or preserving seasonal produce, proper technique makes all the difference. Use tempered glass, leave enough headspace, and label your glassware for safe, effective freezing. 

Reducing plastic waste doesn't mean compromising safety. You can do both. Looking to upgrade your entire kitchen with quality, sustainable tools? 

Explore de Buyer’s French-made cookware designed to last a lifetime, from carbon steel pans to professional bakeware built for everyday use.