If you’re like most people, you’ve probably wondered whether it’s safe to store glass containers in the freezer.
While the freezer is a convenient place to preserve food and chill drinks, not all types of glass are created equal when enduring cold temperatures.
In this blog post, we’ll delve into the do’s and don’ts of keeping glass in the freezer, helping you to avoid potential hazards.
Can You Put Glass In The Freezer?
Yes, you can keep glass in the freezer, but only if it’s designed to withstand extremely cold temperatures (tempered glass). Not all glass containers are freezer-safe, so be cautious to avoid breakage or potential hazards.
Why Does Glass Break In The Freezer?
The most common reason for a break to break in the freezer is something known as Thermal Shock.
Thermal shock can happen when a glass container, originally at room temperature or warmer, is placed directly into a freezing cold environment. The sudden drop in temperature causes the outer layers of the glass to contract rapidly while the inner layers, which are still relatively warmer, resist this change. As a result, the glass becomes internally stressed, and if it cannot withstand the pressure, it may shatter.
Lack Of Room for Expansion
When a glass container is placed in the freezer, its contents (such as liquids) tend to freeze and expand. Therefore, if there isn’t enough room for this expansion to occur, the glass may crack or shatter under the pressure.
To avoid this issue, it’s essential to leave enough space or headroom in the container before placing it in the freezer. Generally, it’s recommended to fill glass containers only about three-quarters full when freezing liquids to allow room for expansion to avoid putting excessive stress on the glass.
Defects or Imperfections In The Glass
Defects or imperfections in the glass container refer to any cracks or weak spots on the material.
When glassware contains such defects, it becomes more susceptible to breaking, especially when exposed to extreme conditions, including freezing in the freezer.
How to Stop Glass From Breaking in the Freezer
Choose Freezer-Safe Glassware
Not all glass containers are designed to withstand extreme temperatures. When selecting glassware for freezing, opt for those labeled “freezer-safe” or “oven-safe up to freezer temperatures.” These containers are made from durable, thermal-shock-resistant glass, reducing the risk of breakage due to rapid temperature changes.
Allow Room for Expansion
One of the primary reasons glass can break in the freezer is the lack of expansion room for freezing liquids or foods with moisture content.
Always leave some space (about 1 inch) between the food or liquid and the top of the glass container. This extra room accommodates the expansion that occurs during freezing, preventing excessive pressure on the glass walls.
Avoid subjecting glass containers to extreme temperature shifts. Allow hot or warm food to cool to room temperature before placing it in the freezer. Similarly, when taking frozen items out of the freezer, allow them to thaw gradually in the refrigerator or at room temperature to avoid sudden temperature changes that can stress the glass.
Inspect for Defects
Before using any glassware in the freezer, carefully inspect it for defects, imperfections, scratches, or chips. Weak spots can compromise the integrity of the glass, increasing the risk of breakage during freezing. If you notice any flaws, it’s best to avoid using that container in the freezer and invest in high-quality replacements.
When it’s time to use the frozen contents, thaw them gradually in the refrigerator rather than using the microwave or exposing the glass to hot water. Slow thawing helps minimize temperature stress on the glass, reducing the chances of breakage.
Following these practical tips, you can preserve your glass containers, avoid breakage in the freezer, and extend their lifespan.