How can I tell when buying if china will get hot in the microwave?

June 27, 2018 2:18 PM

I want to buy new dishes. How can I tell before buying if the dishes will stay cool in the microwave?

We have two sets of everyday dishes. Both say on the bottom that they are microwave safe, dishwasher safe china. One set gets super hot in the microwave (and the food not so hot), and the other stays cool to the touch with the food warming more quickly. I want to buy new dishes. How can I tell before buying if the dishes will stay cool in the microwave?

posted by amro to Home & Garden (16 answers total)

Anything that is "stoneware" will definitely get hot. I acquired a couple of stoneware plates somehow and they're horrible in the microwave, they're noticeably chunkier and heavier than my regular dishes. I haven't had the same problem with anything that's actually porcelain.
posted by stillnocturnal at 2:36 PM on June 27, 2018 [1 favorite]

Response by poster: Should have noted: both sets also say “Stoneware” on the bottom. Both are of the fairly chunky variety (every day stuff as opposed to special occasion china).
posted by amro at 2:41 PM on June 27, 2018

What microwave-safe really means

Stoneware vs earthenware

Your best option might be to buy a single piece of whatever it is you want to buy and test it.
posted by Everydayville at 2:59 PM on June 27, 2018 [4 favorites]

I don't know how to really tell without zapping them to test, but I can confirm that every piece of fiestaware I have (about six dinner sets plus big bowls and mugs acquired over a few years mostly during macy's sales) does not get hot in the microwave. This is in comparison to the many different dishes I had cobbled together from student living and the years after that, which all got really hot to some degree.

When I went all-in on the fiestaware it was purely for aesthetic reasons and I was surprised by the difference in microwaving, so I looked into it. Apparently it's kind of a crapshoot, but has to do with porosity of the material? If your ceramic or stoneware plates are fully glazed and sealed off from any moisture there's not much in them to get vibrated by the microwaves. But if your plates have cracks in the glaze or it's not well sealed or the material is naturally porous then water can get in there and even though it seems completely dry on the outside there's still enough in there to get really hot when zapped. I have not investigated this myself, just read forum posts online about it out of curiosity a few years ago. Looking at my fiestaware plates the glaze does seem to completely coat them and though some wear shows up there aren't any cracks despite heavy use. Do your stoneware dishes that get hot have any exposed parts or cracks, like maybe around the bottom?
posted by Mizu at 3:07 PM on June 27, 2018 [1 favorite]

Corningware/Corelle doesn't get hot either. My set is vintage, but if they make it the same as they always have (I think it's tempered glass), the only part of the plate that gets hot is the part touching the food. It's also nice, because they're thin. I have something like 25-30 of these plates and they take up less space than my old 8-piece stoneware plates.
posted by dogmom at 4:06 PM on June 27, 2018 [6 favorites]

But if your plates have cracks in the glaze or it's not well sealed or the material is naturally porous then water can get in there and even though it seems completely dry on the outside there's still enough in there to get really hot when zapped.

I'm not posting here for the sake of arguing, but I do want to provide my own anecdotal evidence to the contrary. I have a bowl that I painted, glazed, and kilned at a paint-your-own-pottery studio. Lately I've noticed that it has a variety of chips in the glaze across the rim of the bowl. This bowl continues to not heat up in the microwave.

I use that bowl in the microwave specifically because it doesn't heat up, unlike another bowl I have that was purchased from Pier One. The Pier One bowl will heat up and will actively burn if you're not careful. It seem to have been made in Mexico. I always assumed that it was the type of glaze used on ceramics that determine how hot they get (possibly related to lead in the glaze?).
posted by hydra77 at 4:23 PM on June 27, 2018 [1 favorite]

Per some instruction I got when we got our first microwave circa 1980, one of the hazards is a glaze that gets hot. We have some older china (ordinary clay-type) which is definitely like that. Our current every day dishes are perhaps 20 years old and they are all (or mostly) marked microwave safe. I think that for most anything you buy new, you can find some declaration by the manufacturer on the product or in product description, and I doubt any mass marker manufacturer is selling anything not microwave safe.

That said, in use, some other issues can arise. For example, when you 'wave a mug, you have to head the mug as well as the water. I 'wave heavy mugs for 2 minutes. If I 'wave a light mug for the same amount of time, the thin handle gets very hot.
posted by SemiSalt at 5:44 PM on June 27, 2018

I think there can be an issue with properties of the glaze itself that can cause the plate to heat up. I have a set of small plates that have colorful, painterly glazes...sketches of cheeses or grapes, that kind of thing. I discovered the hard way that even a few seconds in the microwave will turn the plates murderously hot. Like, second-degree burns hot. They’re glazed all over, top and bottom. I can only assume the glazes contain traces of metals of some kind.
posted by Thorzdad at 7:45 PM on June 27, 2018

I use stoneware mugs daily; they don't get hot except from the coffee in them.

If a dish has moisture in it, it would likely explode in the microwave if cooked for any length of time.

Buy the dishes you like, but make sure the store was a basic returns policy. If they get too hot, return them.
posted by theora55 at 8:00 PM on June 27, 2018 [1 favorite]

How can I tell before buying if the dishes will stay cool in the microwave?

Ask the sales person to let you test them in the store's lunch room microwave oven.

"Microwave safe" just means they're not going to break or catch fire if you nuke them. It doesn't mean you're going to be safe if you touch them afterwards.
posted by flabdablet at 8:37 PM on June 27, 2018

Mizu, I have tons of fiestaware and it all gets way too hot in the microwave (and the food is often still cold after you can no longer pick up the bowl). I was thinking that maybe it’s because mine is mostly older stuff from the 80s or early 90s but I just went and microwaved water in an old 80s yellow bowl and a newer plum bowl and they both got too hot. The plum got a little hotter, but maybe that’s because it’s a darker color? I guess the plum is a kind of old color too though. Weird! Maybe the newest colors don’t heat up.
posted by artychoke at 9:20 PM on June 27, 2018

Seconding Corelle. Doesn’t hold heat, is microwave/dishwasher/oven safe, plus the stuff is lightweight, unbreakable, thin, stackable, inexpensive, and comes in many patterns including plain old snowy white.
:)
posted by wowenthusiast at 9:22 PM on June 27, 2018 [2 favorites]

This won't help but I can say that there have been a few mugs I've had that were stoneware (hand-done not mass-produced) that didn't get hot when I first got them but gradually did start to get hotter later in their life. I looked for an answer to this online too a while back and I don't see a definitive answer. I'll be following this thread.
posted by Rufous-headed Towhee heehee at 12:09 AM on June 28, 2018

My fiestaware (early 2000s era) also gets crazy hot in the microwave. It's frustrating. Corelle is great for this issue but for me the thinness feels too delicate, even though I grew up with the stuff and know how durable it is. I guess I just like beefier-feeling dishes.
posted by misskaz at 6:35 AM on June 28, 2018 [1 favorite]

I can add as ancedata that the Ikea Dinera and Vardagen pieces I have don’t get overly hot and actually heat the food.
posted by romakimmy at 1:08 PM on June 28, 2018

Corelle is much better for not heating up as much in a microwave than anything else I've tried. It will still get hot where it's in contact with hot food, so it's not quite a panacea, but if the food is that hot you'd burn your mouth on it anyway, so I figure it makes sense to let it cool a couple of minutes to the point where it's not as much of an issue. They don't retain heat like my old stoneware dishes, which makes them great for microwaving, but not so great for keeping a hot dish warm for long. It's all a bit of a tradeoff. I suspect the molecules in stoneware are just polar enough that the stoneware itself can heat up even in the absence of food.
posted by Aleyn at 2:23 PM on June 28, 2018