Do the test
Pottery is pretty sturdy. It is fired at very high temperatures, so heating it up in the microwave for a while is usually harmless. Exceptions to that rule are pots decorated with gold, silver, or other precious metals,also known as luster. You also shouldn’t put bisque fired work in the microwave. It can damage the pot, and it’s also not food safe.
Let’s look at pottery you’ve bought from a store. Often you’ll see an icon or some text on the bottom to indicate whether the piece is microwave safe. If you can’t find any indication, or we’re looking at pottery you’ve made yourself, here’s what you do. There is a simple test you can do to find out if a ceramic piece can be microwaved.
- Take a mug or glass that you know to be microwave safe. Add water until it’s three-quarters full.
- Put the mug or glass in the microwave, together with the piece of pottery you want to test.
- Put the microwave to the highest setting, and let the pot and the mug or glass warm up for one minute.
- Check whether the water in the mug or glass has warmed up or not. If the water is still cold and the pot is warm, you can conclude that the pot absorbs warmth, which makes it unsuitable for microwaving. If the water is warm and the pot is cold, you can conclude that it’s safe to put in the microwave.
- Make a mark on the bottom, so you can remember which pieces are microwave safe and which are not.
Extra precautions
In prinicple, pottery can easily withstand high temperatures. It’s only problematic if the pottery goes from a cold environment to those high temperatures very quickly, or vice versa. The temperature difference gives it such a shock, that it can cause the clay to crack. So if you want to avoid cracks, your best bet is to avoid shocking temperature diffferences like that.
- Never heat up your pottery while it’s empty. Always make sure it’s at least half full.
- If the pot just came from the fridge, it’s better to not immediately put it in the microwave. Wait until it reaches room temperature first.
- Don’t skip preheating your oven. This allows your pot to warm up slowly, at the same speed as the oven.
- Did the pot warm up completely in the oven or microwave? Don’t immediately rinse it with cold water. Let the pot cool down first.
- If you want to put boiling water or very warm food into a ceramic mug or plate, it’s not a bad idea to run the mug or plate under warm water first, so the clay can warm up a bit.
With these precautions, you can rest easy. Your pottery is safe, even microwave safe!