Opalware is another dinnerware material type. It claims to be microwave-safe, dishwasher-safe, and refrigerator-safe. So in regards to it being microwave-safe, yes it is. Keep on reading to find out how microwave-safe it is.
Opalware or opal dinnerware is made of opal glass. It has a signature milky hue that matches any dining room presentation, setting, or interior design. It’s a nontoxic, non-porous kind of glass with no chemicals in it. Therefore, it’s 100 percent hygienic, easy to clean, and perfectly food-safe.
Additionally, it’s freezer water safe, dishwasher-safe, BPA-free, and microwave-safe. So is opalware microwave safe? Yes, but keep on reading to find out more about it and opal glass.
Is Opalware Microwave-Safe or Not?
Yes. Because the material isn’t porous like stoneware, it’s unlikely that water could enter inside it that the microwaves could then heat up to incredible temperatures that could result in the material breaking like non-Pyrex glass due to thermal shock.
You can reheat food inside the microwave without fearing of damaging opalware. It’s also microwave-safe in that it’s nontoxic and won’t leach harmful chemicals when heating via microwave radiation. You can easily store certain dinnerware in set nests and stacks because they’re all perfectly stackable.

Are You Absolutely Sure It’s Microwave-Safe?
Yes. However, don’t take our word for it. Do a cup of water test on it (might involve ice water or tepid water microwaved to boiling by your microwave’s peak power). If it comes off as a little hot or very hot afterwards, that’s an indication of it not being microwave-safe.
Some opalware don’t have as much microwave-safeness as other opalware due to how thick the material is or the quality of the opal glass used. A perfectly high-quality opalware dinner set should resist microwave radiation perfectly fine.
Read more: So, Does Ceramic Get Hot in the Microwave or Not?
What Things Should You Avoid Doing with Opalware?
For the average opalware dinner plate measuring 8.5 inches by 7.5 inches, you should not use them on the stovetop or broiler. They break easier on such places. Don’t use them as bakeware either. Get a ceramic or Pyrex bakeware instead. Don’t drop it at a great height either.
On top of being as microwave-safe as Pyrex bakeware or most ceramics, it’s also safe to use with your dishwasher and freezer. It doesn’t contain any chemicals and it doesn’t leach off BPA unto your microwaved food like many plastic containers out there. It can even be stacked.
Is Opalware like Ceramic or like Glass?
Opalware features glass-like properties because it’s made of what’s known as opal glass. The main comparison between it and ceramic is that it’s also microwave-safe, dishwasher-safe, and freezer-safe.
All three types of dinnerware material—ceramic, glass, and opal glass—can also break when dropped at a certain height or by blunt force. They’re better than wood or bamboo in that they don’t become fragile or disappointing after a mere minute of microwave radiation exposure.
Opalware is safe to use on most things except on your stovetop, oven, or broiler. This also includes the convection mode or broiler mode of your convection microwave.
What is Opalware Made Of?
Opalware dinnerware and crockery is made of opal glass. In turn, this glass has properties of being heat-resistant and opaque made as white as ceramic by adding bone ash to it. This gives opalware a ceramic-like look despite being made of a type of glass.
It’s one of the safest materials for dinnerware, cookware, and bakeware. To be able to use opalware for microwaves, conventional ovens, and the like, you should get the right type of ware. Opalware bakeware differs in heat resistance compared to dinnerware, for example.
Opalware cookware also uses ceramic cookware, cast iron, 304-grade stainless steel, and so forth to aid its ability to cook food. Wathc out when using pitted pans with deep scratches because metals like chromium and nickel can migrate to food in trace amounts.
How Safe for Your Health is Opalware?
The higher the quality of your opalware the safer for your health it ends up being. We recommend the ones made in Spain and designed by Korea rather than the ones made in China since Spain specializes in Opalware more.
Opal glass dinnerware is nonporous, so dish water or oil won’t end up inside of it, which could then heat up in seconds or a minute using the microwave. It doesn’t absorb food particles that could result in rotting food and a bacterial spread from within.
This makes your dinnerware 100 percent hygienic and food safe. It’s also thermal shock resistant due to its nonporous nature, making it microwave-safe and dishwasher-safe at the same time.
How Do You Test Opalware for Microwave Safeness?
In order to test your opalware dinnerware or bakeware for microwave safety, do the following.
- Get a dish and a separate cup of water on a microwaveable cup, mug, or glass.
- The water could be ice cold (but no ice cubes) or tepid and straight from your tap water.
- It could be filled ¾ of the way with water. Make sure the cup itself is microwave-safe, especially if it’s a plastic or glass measuring cup.
- The point here is to put the opal glassware with the cup of water for microwaving at peak power to check the microwaveability of the opalware in question.
- Check if there’s a microwave-safe stamp on the bottom of the cup and again on the opalware.
- Some (not all) chinaware or earthenware feature the microwave-safe label but some might not, which doesn’t necessarily mean they’re not microwave-safe (hence the test).
- Microwave the dish with the glass of water. The glass could be side-by-side with the dish or directly on top of the bowl.
- The default of many a microwave is peak power but you can increase the power using the Power, Menu, or Settings button.
- Do the test until 2 minutes or the water starts boiling. If the dish is as warm or hot as the water it’s not microwave-safe. Otherwise, if it remains cool while the water boils, it’s microwave-safe.
Issues to Take Note
Many opal dinnerware or opalware sets claim to be microwave-safe. However, you can actually test how microwave-safe they are using the glass or cup of water test. Put in a cup of tepid or ice-cold water inside a microwave with an opalware dish or bowl below it.
Microwave it to boiling. Check the state of both the opalware dish and the cup of water. If the opalware is as hot as the water or even hotter then it’s not microwave-safe. If the opalware remains cool even as the water ends up boiling then it’s microwave-safe.
References:
- Liming Coanhas, “Is Opalware Safe?“, EverythingWhat.com, March 25, 2021
- Raymond Chiu, “How to Test if a Dish Is Microwave Safe“, WikiHow.com, March 24, 2021
- “The Tableware Fiore Opal Tempered Glass Dinnerware Set of 4 (Oval Plate Small)“, Amazon.com, December 10, 2021