Are your mugs oven-safe? Find out which mugs can go in the oven and how to prevent them from damage.
Recently, my friend asked me which coffee mug she should use to bake a mug-cake in the oven. Apparently, she had come across an enticing mug-cake recipe but she was unsure of the type of mug to use.
I did not know that baking with mugs is a thing so I went digging for a conclusive answer and this is what I found out.
Are mugs oven safe?
Yes, stoneware mugs and some porcelain, metallic, and glass mugs that are labeled as oven-safe can go in the oven. However, they can still crack or shatter when subjected to sudden temperature changes. Plastic and paper mugs should not go in the oven.
When used properly, oven-safe mugs will not crack or leach chemicals to the food at high heat or when they are removed from the oven.
How to Tell if a Mug is Oven Safe
Imagine painstakingly preparing the ingredients for your mug-cake only to bake it in a mug that is not oven-proof which ends up shattering and ruining what would have been a delicious indulgence. Even more depressing is that you lose a coffee mug and now you have to clean the soiled oven.
To avoid this, check whether the mug you intend to use is oven-proof. Flip the mug upside down and look for an “oven-safe” symbol, usually an image of an oven with or without vertical wavy lines, at the bottom of the mug.
Alternatively, check whether the packaging specifies that the mug is oven-safe. The manufacturer may also indicate the highest temperature that the mug can withstand.
If both the packaging and the mug do not have an oven-proof stamp or you are still unsure, identify the manufacturer of the mug and head over to their website to ascertain whether the mug can go in the oven.
The materials of the mug will also guide you to determine whether the mug is likely to be oven-safe. For example:
- Stoneware. Stoneware mugs are fired at extremely high temperatures and are thick and sturdy. They can withstand the high temperatures in the oven without cracking. Stoneware is an excellent choice for baking due to
- it distributes the heat evenly
- However, if the stoneware mug has decorations that were made after the final firing process then it should not go into the oven
- Metal. Mugs that are purely metallic without a nonstick finish or plastic parts can safely go in the oven
- Porcelain. Like stoneware mugs, non-decorated porcelain mugs are generally oven proof
- Bone China. The elegant Bone China mugs usually have decor elements on the sides of the mugs and sometimes inside the mug. Bone China should never go in the oven
- Enamel. Enamel mugs are very versatile and can not only go over a fire but can also be used in the oven. They can withstand up to 500°F. However, enamel mugs that are decorated after the glaze firing are not safe for the oven
- Glass. Some glass mugs such borosilicate glass mugs are resistant to extreme heat and can go in the oven. They also have a higher resistance to thermal shocks than regular glass. Check underneath the mug for an oven-proof mark
- Melamine and plastic. Plastic mugs will melt in the oven. Although some plastic cups are microwave safe, oven temperatures are considerably higher and will melth the mugs
You can head over to this article that details the best materials for a coffee mug.
Why Stoneware Mugs are the Best Choice for Mug-cakes
- Stoneware mugs provide a natural non-stick surface. You do not have to oil the mug to remove the mug
- Heat retention and even baking. Stoneware is thick and retains heat longer and distributes it evenly. The cake is, therefore, evenly baked
- Heat resistance and durability. Stoneware mugs are fired at over 2100°F during manufacturing and can therefore withstand very high temperatures during baking. Their thickness makes them sturdy even at high temperatures
- Rustic appeal. The rustic appearance of stoneware mugs has a special appeal
- Versatility. Stoneware mugs are both oven-safe and microwave-safe unlike metallic mugs
Should Decorated Mugs Go in the Oven?
Most mug decorations are added after the final firing when making the mug. The decorations are therefore likely to be unsafe to face the extreme temperatures in the oven.
As a rule of thumb, treat all decorated mugs – whether they are glass, stoneware, metallic, or even enamel mugs – as unsafe for the oven unless the manufacturer has clearly stated that the mug can go in the oven.
Do you have some scratched mugs at home or in the office? See our article about scratched mugs and whether you should use them
Does Microwave Safe Mean Oven Safe?
No, a microwave-safe mug is not necessarily oven-safe. For example, microwave-safe plastic mugs work fine in the microwave but they will easily melt when subjected to high temperatures for a longer duration in the oven.
A mug that is both microwave safe and oven safe will have both symbols underneath it or on its packaging.
Similarly, oven-safe does not always mean microwave safe. Metallic mugs including enamelware may be safe in the oven but should not go in the microwave as metals reflect the microwaves and can damage the interior of the appliance.
They can also cause sparking inside the microwave and even fire as the air around the metallic mug’s edges is ionized.
10 Tips to Prevent Oven-safe Coffee Mug from Cracking
- Avoid suddenly changing the temperature of the mug. Avoid bringing the mug straight from the fridge or freezer into the oven or from the oven and cooling it rapidly. Instead, leave the mug on a countertop to gradually achieve room temperature by itself and then use it in the oven or in the refrigerator
- Use the oven-safe mug within the recommended temperature. Some mugs can only withstand up to 350°F whereas others can withstand about 500°F. Confirm the maximum temperature that the mug can handle before deciding whether it’s fit for your recipe
- Avoid subjecting hot mugs from the oven to any type of force. Porcelain mugs have very thin walls and can easily crack or shatter from any compressive force especially when they are hot
- Do not use decorated mugs in the oven even if the mug’s material is oven-safe. Decorations on the mug affect the way heat is distributed on the surface of the mug and can cause some parts to expand more than others. This can cause the mug to shatter. Worst-case scenario, the mug does not shatter but the decorations will melt and leach their chemicals to the cake which may cause health issues. Some decorations may ignite under high heat
Generally, oven-safe mugs have a print on the bottom side of the mug or on the packaging indicating that they can be used in the oven. Stoneware mugs are the best choice for the oven.
Other oven-safe include porcelain mugs, purely metallic mugs, enamel mugs, and some glass mugs.
Mugs with decorations are likely to be unsafe for the oven even if the material of the mug is oven-safe and you may want to avoid baking in them.
Avoid causing sudden temperature changes on the oven-safe mug to prevent cracking. You may also want to check the maximum temperature that the mug can withstand before commencing the baking process.