# "Do not heat rice cakes in toaster or microwave" - why not? **URL:** \ **Category:** Factual Questions\ **Created:** [January 12, 2008, 9:02pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325 "2008-01-12T21:02:33Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![MsWhatsit](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@MsWhatsit](https://boards.straightdope.com/u/MsWhatsit)\ **Post date:** [January 12, 2008, 9:02pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/1 "2008-01-12T21:02:33Z")
Title says it all, really. I have here a package of Quaker rice cakes and there’s a warning on the side instructing the consumer not to heat the product in a toaster or microwave. Why not? Will it explode or something? I’d try it myself but, you know, I _just_ cleaned out the microwave, so I thought I’d ask here instead. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [January 12, 2008, 9:15pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/2 "2008-01-12T21:15:51Z")
They could start a fire. Rice cakes are very low moisture and can easily catch fire if overheated. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [January 12, 2008, 9:24pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/3 "2008-01-12T21:24:36Z")
And besides, they’re [dangerous](http://www.foxnews.com/story/0,2933,240683,00.html). 😃 ---
**Author:** ![MsWhatsit](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@MsWhatsit](https://boards.straightdope.com/u/MsWhatsit)\ **Post date:** [January 12, 2008, 9:35pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/4 "2008-01-12T21:35:22Z")
Huh. I did not know that. Ignorance successfully fought! ---
**Author:** ![Contrapuntal](https://avatars.discourse-cdn.com/v4/letter/c/e274bd/32.png) [@Contrapuntal](https://boards.straightdope.com/u/Contrapuntal)\ **Post date:** [January 12, 2008, 9:38pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/5 "2008-01-12T21:38:37Z")
[QUOTE=Q.E.D.] They could start a fire. Rice cakes are very low moisture and can easily catch fire if overheated. [/QUOTE] I thought microwaves worked by exciting the water molecules. Am I wrong? If I’m right, wouldn’t a very dry product be at low risk for overheating? Any idea what the combustion temperature of rice is? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [January 12, 2008, 9:46pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/6 "2008-01-12T21:46:13Z")
[QUOTE=Contrapuntal] If I’m right, wouldn’t a very dry product be at low risk for overheating? [/QUOTE] It isn’t just water. Fats, sugars and other substances also absorb MW radiation; anything which has at least a weak electric dipole. The presence of water, however, keeps things from getting too hot, since the evaporating water carries off excess heat energy. Without much water, a rice cake could get very hot indeed. Popped popcorn is also very dry–ever leave a bag in the microwave a bit too long? That said, I’d place the risk of a rice cake fire in a microwave oven at the low end of the risk scale. But, it _can_ happen and as sure as the sunrise, some moron would sue over it. Hence, the warning. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [January 12, 2008, 9:51pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/7 "2008-01-12T21:51:13Z")
I might add tortilla chips to that list. I once put a plate of them (chips only, not nacho cheese or salsa) in the microwave, thinking it would crisp them up, as they were slightly stale. After less than a minute, an acrid cloud of yellow smoke began leaking out of the microwave, and they nearly burst into flames when I opened the door. ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [January 12, 2008, 9:51pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/8 "2008-01-12T21:51:20Z")
[QUOTE=Q.E.D.] Popped popcorn is also very dry–ever leave a bag in the microwave a bit too long? [/QUOTE] Best… Good Eats… episode… ever. No, Alton didn’t burn some popcorn, but clued me in on the fact that you can pop it without oil. Some lunch bags, a couple of staples (you already have the stapler, right?), and bag of regular popcorn will set you back about $3, and yield about $100 “worth” of microwave popcorn. Add a little more cost if you like butter. In fact, if you throw a pat or two of butter in the bag (or an adequate quantity of flavoured oil), then you get the flavour you want. I prefer the non-fat variety, m’self. (And face it, that’s why you’re eating rice cakes, right?) ---
**Author:** ![MsWhatsit](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@MsWhatsit](https://boards.straightdope.com/u/MsWhatsit)\ **Post date:** [January 12, 2008, 9:58pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/9 "2008-01-12T21:58:58Z")
[QUOTE=Balthisar] (And face it, that’s why you’re eating rice cakes, right?) [/QUOTE] Actually, I feed them to the kids. My daughter loves the cursed things. Thanks for the tip re popcorn, though! We go through a truly stupid amount of microwave popcorn around here, and I am now en fuego (no pun intended) to try this new method. ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [January 12, 2008, 11:13pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/10 "2008-01-12T23:13:32Z")
And don’t worry about the staples in the microwave. They’re shorter than the wavelength of the microwaves and have very little mass so they shouldn’t heat up. ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [January 12, 2008, 11:35pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/11 "2008-01-12T23:35:53Z")
[Alton’s method](http://www.foodnetwork.com/food/recipes/recipe/0,,FOOD_9936_11374,00.html) ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [January 13, 2008, 1:17am UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/12 "2008-01-13T01:17:23Z")
[QUOTE=Ferret Herder] [Alton’s method](http://www.foodnetwork.com/food/recipes/recipe/0,,FOOD_9936_11374,00.html) [/QUOTE] Don’t feel that you need the oil in his method, though. Definitely works without anything but the popcorn. > [@jayjay](#): > > And don’t worry about the staples in the microwave. They’re shorter than the wavelength of the microwaves and have very little mass so they shouldn’t heat up. Generally speaking, the only metals I have problems with in the microwave are aluminium foil. When it’s crinkly (and it generally is), the peaks seem to arc out against each other. I heat things up with metal spoons, and even use stainless steel bowls. I _do_ seem to remember from when I was a kid, though, that there were special “microwave safe” paper towels, because paper towels had metal fibres in them? Sounds absurd, I know, but children are impressionable. Man, microwave ovens seemed like such an awesome thing back then, but now, mine is an expensive popcorn popper and is handy for reheating. ---
**Author:** ![danceswithcats](https://avatars.discourse-cdn.com/v4/letter/d/9e8a1a/32.png) [@danceswithcats](https://boards.straightdope.com/u/danceswithcats)\ **Post date:** [January 13, 2008, 1:24am UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/13 "2008-01-13T01:24:20Z")
[QUOTE=jayjay] And don’t worry about the staples in the microwave. They’re shorter than the wavelength of the microwaves and have very little mass so they shouldn’t heat up. [/QUOTE] But they may get stuck in your teeth. ---
**Author:** ![Acehrt](https://avatars.discourse-cdn.com/v4/letter/a/a6a055/32.png) [@Acehrt](https://boards.straightdope.com/u/Acehrt)\ **Post date:** [November 10, 2014, 6:50pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/14 "2014-11-10T18:50:16Z")
> [@Q.E.D](#): > > They could start a fire. Rice cakes are very low moisture and can easily catch fire if overheated. Rice cakes alone should not be heated in the microwave. but if you add a slice of cheese and a slice of tomato, you can put it in the microwave until the cheese melts. Keep a close eye on it. Usually about 10 seconds. These are so yummy I got the rest of my family enjoying them. Have been doing this for years now. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [November 10, 2014, 6:54pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/15 "2014-11-10T18:54:32Z")
> [@Contrapuntal](#): > > I thought microwaves worked by exciting the water molecules. Am I wrong? > > If I’m right, wouldn’t a very dry product be at low risk for overheating? > [@Q.E.D](#): > > It isn’t just water. Fats, sugars and other substances also absorb MW radiation; anything which has at least a weak electric dipole. You’re not supposed to run a microwave empty. If the only thing in the microwave is something that can’t absorb microwave radiation, I imagine it’s the same principle. ---
**Author:** ![BubbaDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bubbadog/32/333_2.png) [@BubbaDog](https://boards.straightdope.com/u/BubbaDog)\ **Post date:** [November 10, 2014, 7:07pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/16 "2014-11-10T19:07:22Z")
> [@Acehrt](#): > > Rice cakes alone should not be heated in the microwave. but if you add a slice of cheese and a slice of tomato, you can put it in the microwave until the cheese melts. Keep a close eye on it. Usually about 10 seconds. These are so yummy I got the rest of my family enjoying them. Have been doing this for years now. 10 seconds works fine. Almost 7 years, not so much. Welcome to the dope! ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [November 10, 2014, 7:11pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/17 "2014-11-10T19:11:19Z")
**Moderator Note** This thread dates back to 2008. Sadly, a couple of the posters are no longer with us. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [November 10, 2014, 7:14pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/18 "2014-11-10T19:14:44Z")
> [@Thudlow\_Boink](#): > > You’re not supposed to run a microwave empty. If the only thing in the microwave is something that can’t absorb microwave radiation, I imagine it’s the same principle. Running a microwave empty is a bit harsh on the magnetron (the thing that generates the radio waves). Back in the earlier days of microwave ovens (1970s and early 1980s) you could easily ruin a microwave oven by running it empty. These days the magnetrons aren’t quite so delicate. But it’s still not a good idea to run one empty. And yes, if there’s nothing in there that will absorb the microwave radio waves then that’s pretty much the same as running it empty. ---
**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\ **Post date:** [November 10, 2014, 9:49pm UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/19 "2014-11-10T21:49:50Z")
> [@jayjay](#): > > And don’t worry about the staples in the microwave. They’re shorter than the wavelength of the microwaves and have very little mass so they shouldn’t heat up. I’d worry about tossing down a handful of popcorn and getting a staple down there too. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [November 11, 2014, 1:00am UTC](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325/20 "2014-11-11T01:00:11Z")
> [@Q.E.D](#): > > And besides, they’re [dangerous](http://www.foxnews.com/story/0,2933,240683,00.html). 😃 Perhaps he meant this mis-information as humorous ? Its a different type of rice cake that is the killer in Japan… the choking hazard is due to the use of (misnomer) “glutinous rice”… its a specific crop … and then its made wet and sticky, like chewing gum. In asia they use rice as flour … The flammable rice cake is the puffed rice grains… dry and aerated. [Next page](https://boards.straightdope.com/t/do-not-heat-rice-cakes-in-toaster-or-microwave-why-not/433325.md?page=2)