HOME > Chowhound > Cookware >

Discussion

Is it safe to heat plates in the microwave?

As someone who works in a restaurant I feel the need to plate everything on a hot plate. At home, where I have no plate heater, I have always preheated my plates in the microwave. I was cooking at my friend's house and I put a stack of plates in the microwave to heat them up, and he expressed a lot of concern. I haven't had any problems before, but I have only tried with the plates in my house, which are mostly from Ikea. Is this a bad idea? Could this damage good china or porcelain?

  1. Click to Upload a photo (10 MB limit)
Delete
  1. I'm curious how it works if the plates are dry.

    1 Reply
    1. re: jaykayen

      I was too. But it works. Amazingly well actually. 40 secs to a minute on high and it's the perfect temperature, depending on your microwave. I couldn't believe it the first time I saw it, but I've been doing it ever since. It's the only thing I really use my microwave for.

    2. Your plates from Ikea are probably less fragile than fine china or porcelain and some high end china has gold leaf embossed patterns which would definitely cause a problem in a microwave.

      1 Reply
      1. re: petek

        Yeah I never thought of that. I should add that I just realized that I learned this technique at a tiny 12-seat restaurant in Japan where they heated all their plates this way, so there are plates other than Ikea plates that this seems to work fine for.

      2. I used to do this but then I once had a microwaveable bowl crack so I stopped doing it. Now I just hold the plates or bowls over whatever is giving off the most steam on the stove and then place the plates and bowls near the stove (or on a back burner if not being used) until I serve. Usually does the trick.

        2 Replies
        1. re: ttoommyy

          Was that bowl extremely hot when it cracked? As in too hot to hold in your hand? Or did it just crack inexplicably?

          1. re: la2tokyo

            "Or did it just crack inexplicably?"

            That one.

        2. In theory at least, most pottery is microwave transparent and shouldn't heat. For the plates to heat there must be a contaminant in the construction that is a microwave absorber. Or maybe in the absence of other absorbers the plates do absorb some microwave energy. Porcelain, it typically labeled microwave safe, so I would think that should not be a problem. Anything that can go into the microwave with food on it should be safe when there is no food on it.

          Unless we have misinterperted your friends response, perhaps he was not concerned about the plates at all but was concerned about the microwave. I haven't bought a new microwave in a long time, but it seems like they used to tell you not to run it empty. If the plates are truely microwave transparent then in effect the microwave is empty and there is nothing to absorb the microwaves when you turn it on. Thus they would be reflected by the metal cabinet and could potentially damage the microwave.

          11 Replies
          1. re: mikie

            Hmm, am confused -- I microwave food in my porcelain (apilco and pillivuyt, which I'd think would be less prone to contaminants relatively speaking) and also in stoneware and pottery, and the bowls always come out piping hot (too hot to touch with bare hands) even when the food is not completely hot (?). Can you explain this, or am I misinterpreting the microwave transparent idea?

            1. re: iyc_nyc

              If the bowl is hotter than the contents (especially the rim that is not in contact with any food), you should not be using that bowl in the microwave. If you seal in the steam (with plastic wrap) the bowl will get nearly as hot. But the waves should be heating the food, not the container.

              1. re: paulj

                Wow. Should Apilco and Pillivuyt be doing this (heating up more than the contents, including at the rims of the bowls/plates where food isn't touching), especially when they are said to be microwave safe? I'm now thoroughly confused, as this happens with ALL my bowls and plates, including those of other materials.

                Does anyone else have experience with this, esp with very common French porcelain that is widely stated (including by the mfr and the retailer) to be microwave safe?

                In case it's relevant, my microwave is a standard GE Spacemaker, and we're talking nothing fancy - just reheating food like pasta or soup at 2-3 minutes max, usually at just 2. After 2 minutes, the food isn't hot enough, the bowl is hot, I stir things up and then might put 1 more minute on it. I don't do 3 straight minutes partly bc I figured early on the bowl/plate would be piping hot after 2 minutes and instinctually seemed bad for the bowl/plate, hence the +1 approach.

                1. re: iyc_nyc

                  I agree with paulj. If the plate is hotter than the food, it's not a good plate for use in the microwave.

                  I suspect that "microwave SAFE" just means that you can put the dish in the microwave and it won't crack or explode. However, if the dish absorbs microwaves and becomes hot, that means it's also blocking microwaves from the food, which therefore doesn't get hot enough.

                  I microwave on Pyrex or Corelle dishes. The food gets nice and hot, but the edges of the dish are usually cool enough to handle with your bare hands.

                  PS. Of course, if your dish doesn't absorb microwaves at all, trying to warm it in the microwave oven won't accomplish anything!

                  1. re: tanuki soup

                    Okay, I m-wave in pyrex too - and they get hot! I will test this wkend to make sure, but it's something that's so common and all the time that I always use oven mitts - it's hot!

                    1. re: iyc_nyc

                      If I MW soup in a Pyrex bowl, the bowl will be hot. If I MW a couple of pieces of fried chicken on a Pyrex plate, the rim of the plate will be cool. OTOH, if I MW a serving of lasagna on a Pyrex plate, the rim will be hot. I think it's all about the conduction of heat from the hot food to the bowl or plate. The glass won't be heated directly by the MWs. That's why the rotating turntable in a MW oven is made of glass.

                      1. re: tanuki soup

                        Ok, the turntable example makes total sense and is helpful. I tested tonight (reheating food in apilco) and realized upon removing it from microwave that the rims of the bowl were steamy, no doubt from the food + heat. So this is all consistent with your, Mikie's and Paul's theories.

                        So thanks to all!

                2. re: paulj

                  If you cover the top with plastic wrap the plastic is a by-product of petroleum and is toxic. You should NEVER cover anything with plastic wrap and heat it up. It released TOXIC material into your food and air. I use paper towels, wax paper or another plate over the top.

                  1. re: themadhousecoffee

                    Looks like I'm responsible for reviving this thread. This poster must have done a web search on something like 'plastic wrap in microwaves', and found my post. So far its their only post.

                3. re: iyc_nyc

                  Well, I think everyone has taken a good shot at it already, don't know that I can add much. I've got Apilco and Pillivuyt as well, don't notice them getting any hotter than anything else I put in the microwave.

                  Microwave transparent is simpley something that does not absorb microwaves, or at least not very well. The plates fall into this catagory. This short excerpt explains better than I can.
                  "So-called "microwave transparent" materials such as some glass, pottery, paper and most plastics allow the waves to pass through. When used as containers, these materials do not take up microwave energy, but allow the solutions inside of them to absorb the microwaves. The absorbed microwave energy causes dipolar molecules (such as water) to rotate at the rate of 2.45 billion cycles per second. The interaction between the rotating dipolar molecules, ions and non-moving molecules induces friction, which in turn produces the heat that warms the solution. This is somewhat like the way heat is generated when you rub your hands together. Microwaves heat the solutions from the outside in, just like sources of ordinary heating, but much faster."

                  Those molecules are also touching the plate or bowl, so I would expect the plate to heat up, but it still shouldn't be hotter than the food. My personal observation is that heating in a microwave gets the outer layer very hot very quick, but the inner layer never seems to be hot. I think microwave ovens have gotten so powerful that a 1 or 2 min zap has the outside bubeling hot while the inside hasn't had time to warm up. But your plate is touching the outside of what your warming and it's transfering heat.

                  1. re: mikie

                    The power of a given microwave does have a good bit to do with this, I think. Ours is a 1980s 700-watt, and I do most re-heating on low, finishing with a minute at medium if necessary. At high, there always seems to be the outside-bubbling-inside-tepid phenomenon.

                    When I've used higher-wattage microwaves, that effect seems even stronger -- so it's essential to reheat on low for short bursts, stirring the food in between -- to get even heating. Makes me hope our low-powered Panasonic "Jr." will last a good while longer, or that they're still making 700-watt models.

              2. I microwaved some lentil stew on a white IKEA plate and it cracked in two! Looked on the back and it did not say microwave safe, so beware.