A fridge is one of the most commonly used appliances in your home. It is part of your daily routine to put different food items and containers in the fridge. But can you put hot glass in the fridge?
The answer is a little more interesting than you think!
Table of Contents
- Can You Put Hot Glass in the Fridge?
- What happens if you put hot glass in the fridge?
- What are thermal expansion and thermal shock?
- At what temperature does glass crack?
- How does glass crack from heat and cold?
- Will hot Pyrex break in the fridge?
- Why should you never put hot food in a fridge?
- What should I do if I put hot glass in the fridge and the glass cracks?
- Conclusion
Can You Put Hot Glass in the Fridge?
Glass has a low thermal shock (400oF). Therefore, you should not put hot glass in the fridge. Only glasses made of borosilicate are thermal shock resistant. Borosilicate contains boric acid (5%) that can withstand temperatures up to 550oF. Hot glass in the fridge raises the temperature by 40-140 oF, allowing bacterial growth in the fridge.
| Glass type | Soda lime | Glass | Borosilicate |
| Shock resist. | 92oF | 400oF | 532oF |
| Sio2 | 69 | 71 | 80.6 |
| B2o3 | 1 | 1.5 | 13 |
| Na2O3 | 13 | 12 | 4 |
| Al2O3 | 4 | 6 | 2.4 |
| Kno3 | – | 40 | – |
| Shatter upon cold storage | Yes | Yes | No |
Read more: Does Frozen Meat Weigh More? A Science-Backed Answer
What happens if you put hot glass in the fridge?
If you’ve ever had a cup of tea or coffee that, when it finishes cooling, still feels warm to the touch, you’ve experienced the phenomenon known as the residual heat effect. The residual heat occurs when your hot beverages or food cools faster than your refrigerator can keep up.
Cooling at a slower pace traps the remaining heat in the glass, keeping it from escaping and giving you a slightly warmer drink. The longer the beverage is trapped within the glass, the warmer it will keep after being removed from its container.
To test how much residual heat is trapped within your drinking glass, fill it with tap water and set it on your kitchen counter. Let it sit until all the coolants have drained out before placing it in its storage container for future use.
The colder end of your glass will retain more of its original temperature than the warmer end. It may not seem like much, but if you have a lot of glasses in your collection and plan to store them away for extended periods of time, this little trick could save you some time come springtime!
What are thermal expansion and thermal shock?
Thermal expansion is the expansion of a substance when its temperature changes. For example, water will expand when it cools and contracts when it heats.
Thermal shock happens when a material’s temperature suddenly changes from one extreme to another.
A thermal expansion or shock change can cause the glassware to break under certain conditions. The warmer end of your glass will retain more of its original temperature than the colder end, which can lead to problems such as thermal shock and thermal expansion if you don’t plan for them ahead of time.
Read more: Can you put hot coffee in a red solo cup?
At what temperature does glass crack?
The glass is engineered to have a specific glass transition temperature in which it starts to lose its ability to take the heat and no longer absorb or hold it. This is when the glass transitions from a brittle solid into a liquid state, making it easy to break.
The outside of the glass will start to feel warm if held in your hand. It can also be heard crackling and popping as it cools. When the glass reaches its liquid state, the molecules move fast enough to make an audible sound.
The lower the temperature, the louder this noise becomes until finally reaching a “popping” sound at around -60 degrees Fahrenheit or -51 degrees Celsius (depending on which type of glass you’re using).
How does glass crack from heat and cold?
Glass is a brittle material made of molecules held together by a strong bond. Air bubbles can form when exposed to high temperatures, creating stress within the glass. The stronger the stresses in the glass, the more likely it can crack and break.
When you have your beverage at room temperature, there are practically no stresses in the glass. As soon as you place your cold drink on a warm surface like a table or countertop, the residual heat from that surface causes stress in the glass.
As these stresses cause the glass to heat up, they weaken its bonds and become more prone to breaking.
Will hot Pyrex break in the fridge?
If you have a set of Pyrex dishes, you may have noticed that they are marked with a new symbol on the bottom: a number followed by a cross. The number indicates the dish’s temperature rating, and the “X” means it is for use in the refrigerator.
If your Pyrex dish doesn’t have this design, you can still store it in your fridge because it will be fine without special care. Many plastic dishes can also be stored safely in your refrigerator without fear of them breaking.
Why should you never put hot food in a fridge?
The residual heat effect is beneficial but can also be dangerous for storing food. Never put hot food in a fridge or any other cold container. Doing so will cause the container to shatter, potentially causing injuries to you or your guests.
To avoid this scenario, place your hot glass on a wooden cutting board instead of in a rigid plastic container that will crack and break when the heat inside becomes too high.
What should I do if I put hot glass in the fridge and the glass cracks?
If you’re unfortunate enough to put your drink in the fridge and it cracks, don’t worry!
This is a sign that you are doing something right. The residual heat effect is keeping your drink warm. Rather than throwing it out and buying a new one, try storing it in an airtight container for a few hours or overnight.
If you do this and still have a broken glass, throw it away!
Conclusion
So, can you put hot glass in the fridge? Glass is a material that undergoes thermal shock when heated and cooled rapidly. Put a hot glass in the fridge, which can crack from thermal shock.
