Is Ceramic Microwave Safe

Is ceramic safe for microwave? Ceramic is microwave safe with some safety precautions. You should avoid microwaving ceramic plates with metallic finishing, paint, or trim. In addition, the cold ceramic from the refrigerator shouldn't be heated up immediately.

Ceramics is one of the oldest forms of tableware known to people. It has become an integral part of our lives.

Jump to:

• What is ceramic tableware?
• Is ceramic microwave safe?
• Can you microwave ceramic?
• How to tell if ceramic is microwave safe
• How long can you microwave ceramic?
• Is pottery microwave safe?
• Is porcelain microwave safe?
• Is stoneware microwave safe?
• Is earthenware microwave safe?
• Is terracotta microwave safe?
• Tips for microwaving ceramic
• Is ceramic oven safe?
• Conclusion
• FAQ
• Comments

Ceramic tableware is available in different shapes, sizes, and colors. It brings elegance to any table, but it surprisingly has other benefits. 

It is considered one of the healthiest materials. It is heat resistant, durable, non-porous, non-stick, chemically stable, and doesn't leach harmful chemicals to food, so it is safe for daily use.

What is ceramic tableware?

Ceramic tableware includes ceramic cups, bowls, plates, etc., made from ceramic materials. The most common examples of ceramics include pottery, terracotta, porcelain, glazed earthenware, and stoneware. 

The primary raw material of ceramics is kaolin. It is non-toxic, with low microwave consumption. Therefore, you can put ceramics from this type of kaolin in the microwave. 

If ceramics are made of kaolin with added metallic impurities, they are not suitable for microwave ovens.

Is ceramic microwave safe?

Most ceramic tableware is microwave safe, but you should check if it is labeled "microwave safe."

It isn't advisable to microwave ceramic plates with gilding. The gold powder or dust can melt and contaminate food. 

Moreover, the presence of metal in the microwave is dangerous; the waves will be reflected and damage the microwave oven. So always read the manufacturer’s instructions for your safety and prolonged microwave use.

Can you microwave ceramic?

Nowadays, ceramic plates and bowls produced by modern manufacturers can be microwaved. 

Ceramic dinnerware is heat resistant, so you can safely heat food in the microwave oven. There is no risk of breaking, melting, or leaching in food like Tupperware.

But not all ceramics are heat resistant; some can't withstand heat. For example, if you have vintage ceramic tableware inherited from your grandmother, it may be incompatible with a microwave oven.

Old materials and techniques can result in splitting ceramic dishes and coming out hot after only 1-2 minutes of microwaving.

Even nowadays, not all ceramic vessels are created equal and can withstand extreme temperatures. 

Ceramic products made of less refined clay and fired at low temperatures are porous. Such ceramics can't be put in the microwave.

Ceramic vessels made of pure clay and fired at much higher temperatures are more complex and less porous. This type of ceramic is suitable for microwaving.

You should never microwave colored ceramic bowls. High temperatures can cause pigment precipitation in heavy metals, putting your health at risk.

Those with metal lining and decorations are also dangerous for microwaving. Another precaution relates to cold ceramics from the refrigerator or freezer that should not be microwaved immediately.

How to tell if ceramic is microwave safe

The first thing, please, check if the bottom of the ceramic bowl or mug is labeled "microwave safe" or "microwave friendly." Alternatively, look for three wavy lines that indicate the microwave-safe products.

If you don't see the one, look for the manufacturer's guide online, email, or call the company.

But what to do if your ceramic dish doesn’t have a label, it is made by an unknown brand, or you just bought it on Etsy? To check if you can safely microwave ceramics, perform a simple test.

• Take the microwave-safe mug and an empty ceramic pot you want to test and pour three-quarters of the water into both.
• Place both vessels inside the microwave and heat at high for a minute.
• Using a potholder or oven mitts, take them out of the microwave.

If the ceramic pot you have tested is cool or warm to the touch (be careful!), and the water is hot, this dish is safe to microwave.

If the ceramic dish is warmer than the water inside, it is unsafe for microwaving.

Another test doesn't use water. Place the unlabeled ceramic in the microwave and turn it on high for 20 seconds. If the dish gets hot to the touch (be careful), it isn't safe to microwave it.

Attention: use the oven mitts to handle the ceramic dish from the microwave.

You might not know that ceramics has some water content inside the surface's microcavities. With the introduction of heat, water gets heated. Once the water reaches boiling, ceramic products may crack or even explode.

What's next? Use a permanent marker to label your ceramic. Draw three horizontal waves or write the letter "M" on the bottom of the dish if it has passed the test.

Or opt for a microwave-safe glass or Pyrex container if you are ever in doubt.

How long can you microwave ceramic?

The answer depends on the material the ceramic product is made of. If it is made with a porous material absorbing water of more than 10% of its weight, it can't be microwaved for longer than a minute.

If the ceramic is made with pure clay that absorbs water less than 2% of its weight, you can safely microwave it for a few minutes.

Finally, ceramic dishes embellished with metal or lead-glazed with their finish should not be put in the microwave.

Is pottery microwave safe?

Most pottery labeled "microwave safe" can be safely microwaved. However, if you bought it from an unknown brand, try to search for the type of clay material or perform the microwave test described above.

Refrain from microwaving those pottery bowls or mugs that have metal finishing. Once in the microwave, the metal decorations can cause a fire.

Since pottery gets hot quickly, the required time for heating food is about 1-2 minutes. Don’t heat for an extended period (longer than 5-6 minutes).

Also, be careful with sudden temperature changes:

• Don't place hot pottery on a cold surface.
• Don't put hot food or pour hot drinks or boiling water into cold pottery.
• Likewise, don't run cold water on a hot pottery dish.

Now let's look if three main categories of pottery - porcelain, stoneware, and earthenware - are microwave safe.

Is porcelain microwave safe?

Porcelain is burned at very high temperatures, which makes it durable and non-porous.

Porcelain bowls can be safely heated in the microwave. They withstand high heat, but it depends on the types of porcelain: hard-paste, soft-paste, and bone china which is the highest quality ceramic. Those decorated with a gold rim should not be put in the microwave oven.

Some porcelain plates may crack in case of thermal stress, so try not to put very cold food on a hot plate.

Is stoneware microwave safe?

Most stoneware dishes are microwave-safe, but you should always check the manufacturer's instructions.

Stoneware is well known for absorbing microwaves. So your milk will be lukewarm after heating in the microwave since the stoneware mug absorbs the heat.

For good heating in the microwave, a dish should be "transparent" to the microwaves without absorbing them. So it isn't the case for stoneware.

Still, if stoneware is made with properly composed glazes, it can be used in the microwave. 

Is earthenware microwave safe?

Earthenware refers to opaque, porous ceramics that absorb water. Due to high porosity, it also absorbs microwave radiation and doesn't heat food well. Also, there is a risk of the glaze being crackled while microwaving.

Generally, earthenware dishes are microwave-safe, but not all. Please, refer to the manufacturer's product care instructions. You can opt for more durable porcelain, microwave-safe Pyrex glassware, or glass dishes.

Is terracotta microwave safe?

Terracotta, terra cotta, or terra-cotta is a type of earthenware, porous ceramic pottery with multiple impurities (it isn't very refined). It absorbs microwaves and, as a result, lengthens the reheating time. 

Also, terracotta traps the water inside and may crack and even explode in the microwave. So terracotta isn't suitable for microwaves.

Tips for microwaving ceramic

Despite most ceramics being microwave safe, some safety standards must be considered.

• When purchasing, choose trusted brands, for example, Rörstrand, with its Feldspar porcelain that labels its products microwave-safe. Be careful with handmade ceramics; they might be perfect for decorative purposes, storing and serving food, but not microwaves.
• If the ceramic ware is unbranded, perform a simple test for microwave safety.
• Don't put an empty ceramic bowl in the microwave. Instead, fill it with liquid or food in at least half the bowl.
• Don’t stack ceramic mugs, plates, or bowls in the microwave to warm them.
• Avoid thermal shock, aka rapid temperature change, while using ceramic dishes. Warm up a ceramic mug or plate with running water before pouring boiling water inside.
• Don't microwave cold ceramic. If you take ceramics out of the fridge and place it right away in the microwave, it may break or explode.  You should place the ceramic at room temperature or transfer the food to another microwave-safe bowl and then put it in the microwave.
• Do not overcrowd food in the ceramic dish for even heating.
• Heat similar foods in the microwave to avoid mixing flavors and textures. Better, microwave different foods in different dishes.
• Ensure to reheat food to a proper internal temperature of 165°F (74°C).

Is ceramic oven safe?

Fired ceramic cookware (fired at high temperatures during the manufacturing process) can withstand the oven's heat. So most ceramic pieces labeled "oven safe" can go to the oven with a few precautions.

If your ceramic dinner plate was decorated after it was fired, placing it in the oven could chip and cause the paint to fall off.

You should avoid a rapid temperature shift, aka a thermal shock, such as placing ceramic directly in a hot oven or transferring it from a hot oven to cold water.

But can ceramic crack, and at what temperature does ceramic crack? Even if ceramic is highly heat resistant, it only withstands a specific temperature - up to 3000°F (1649°C).

Please, remember that ordinary ceramic plates have no warranty to use in the oven and may crack or even explode.

Also, ceramic plates with colorful metallic glaze aren't oven-safe. Toxic heavy metal may spill at high temperatures.

Always look for ceramic bowls marked oven safe when purchasing. Look for a manufacturer's stamp "oven safe" on the bottom of the bowl or the product instruction.

Conclusion

Is ceramic microwavable? While most ceramic is microwave safe, it doesn't apply to all ceramic brands. Therefore, it is wise to check ceramic cookware for labels, read the manufacturer's instructions, or perform a microwave test.

If in doubt, use microwave-safe dishes made of glass, Pyrex glassware, or microwave-safe Tupperware plastic containers.

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