# Why can't fries be microwaved? **URL:** \ **Category:** Factual Questions\ **Created:** [June 22, 2003, 2:12am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524 "2003-06-22T02:12:28Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Blalron](https://avatars.discourse-cdn.com/v4/letter/b/35a633/32.png) [@Blalron](https://boards.straightdope.com/u/Blalron)\ **Post date:** [June 22, 2003, 2:12am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/1 "2003-06-22T02:12:28Z")
I’ve noticed that whenever I try to heat up cold french fries in the microwave, they become slimy and gross and wormlike. What causes this? ---
**Author:** ![remisser](https://avatars.discourse-cdn.com/v4/letter/r/b3f665/32.png) [@remisser](https://boards.straightdope.com/u/remisser)\ **Post date:** [June 22, 2003, 2:21am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/2 "2003-06-22T02:21:10Z")
> [@](#): > > \*Originally posted by Blalron \* > \*\*I’ve noticed that whenever I try to heat up cold french fries in the microwave, they become slimy and gross and wormlike. > > What causes this? \*\* There are ways to properly microwave french fries. I’ve found that wrapping them up in a ton of paper towels and microwaved long enough, certain brands of fries can come out crispy, although slightly ‘dry’. You could do some variations on containers used and such. I cook bacon in the microwave in the same fashion. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [June 22, 2003, 2:45am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/3 "2003-06-22T02:45:58Z")
There were several brands of microwave french fries on the market until recently. Each came in a package that contained some kind of reflective device that would warm and brown the fries. Evidently that’s what you’re missing. I haven’t seen them in stores for a while now so I can’t give you more information about just what the reflective devices were made of. ---
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [June 22, 2003, 2:53am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/4 "2003-06-22T02:53:47Z")
Microwave fries are still around. The metallic insert isn’t a reflector, its purpose is to get _hot_. [http://www.cosuninbusiness.com/uk/nieuws/magnetronfrites.aspx](http://www.cosuninbusiness.com/uk/nieuws/magnetronfrites.aspx) ---
**Author:** ![Zenster](https://avatars.discourse-cdn.com/v4/letter/z/cdc98d/32.png) [@Zenster](https://boards.straightdope.com/u/Zenster)\ **Post date:** [June 22, 2003, 3:05am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/5 "2003-06-22T03:05:50Z")
Raw potatoes only gain that delightful crisp shell through conversion of their sugary starches into a semi-carmelized crust. The even mass heating of a microwave oven is not at all similar to the surface reaction of an immersion (deep) fryer. You are essentially “dry-boiling” your fries to death. Ergo, the overcooked texture and entirely uncontaminated-by-browning exterior. A microwave oven would tend to mobilize (evaporate) _all_ of the water in each potato piece and dry it out before any browning could occur. I doubt that the rather narrow emission wavelength of its klystron energy source would even thermally activate an oil coating on the raw potato slices. This is why I suspect that nearly all of your frozen microwavable French fries have already been fried beforehand. You are most likely just reheating them. An inability to brown foods is one of the principal limitation of microwave ovens. Energy absorbtion foils help to an extent but do not completely overcome this principal issue. ---
**Author:** ![remisser](https://avatars.discourse-cdn.com/v4/letter/r/b3f665/32.png) [@remisser](https://boards.straightdope.com/u/remisser)\ **Post date:** [June 22, 2003, 3:18am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/6 "2003-06-22T03:18:32Z")
Though don’t go wrapping your fries in tinfoil. Tinfoil does not belong in an oven. I find, if your microwave oven has extra settings, you can set the heat on low, that helps in keeping some of it’s natural water stay inside of it. ---
**Author:** ![vasyachkin](https://avatars.discourse-cdn.com/v4/letter/v/c5a1d2/32.png) [@vasyachkin](https://boards.straightdope.com/u/vasyachkin)\ **Post date:** [June 22, 2003, 3:44am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/7 "2003-06-22T03:44:30Z")
the problem with microwaving anything, is you can only achieve 100 degrees celsius ( 212 F ). above that the water starts to evaporate, and water is what is heating things up in there. ( microwave energy is tuned to resonant frequency of water molecules ). by actually frying stuff, baking it or better yet deep-frying it you can achieve ( if only on the surface of product ) temperatures that well exceed 100 degrees C. and such temperatures are what’s required to brown stuff, make it crispy. with microwave you are basically steaming your food. ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [June 22, 2003, 5:10am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/8 "2003-06-22T05:10:54Z")
Jeezus, folks, he’s RE-HEATING the fries – they’ve already been fried, browned, crisped, and had their starch converted. The crispness of french fries is entirely on the outside; when they’re fried, moisture boils out of the surface (and, in so doing, prevents the oil from soaking in) and the starches at the surface get caramelized (as Zenster says). Both of these make the fresh french fry a crisp delight with a soft and tantalizing center. When you let the fries sit too long, moisture migrates out from the center to the surface, softening it. When you microwave the already-compromised fries, the heat and steam demolish what’s left of their former rigor, and they become limp as a speed-curl in Houston. Note: a truly well-browned french fry will stand up to aging, and even microwaving, better than the fast-food standard. Alas, the spud-spawn of McDonald’s is merely blond, and its rigor is ephemeral as Bob Dole’s (pre-Viagra). ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [June 22, 2003, 5:16am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/9 "2003-06-22T05:16:15Z")
Jeezus, folks, he’s RE-HEATING the fries – they’ve already been fried, browned, crisped, and had their starch converted. The crispness of french fries is entirely on the outside; when they’re fried, moisture boils out of the surface (and, in so doing, prevents the oil from soaking in) and the starches at the surface get caramelized (as Zenster says). Both of these make the fresh french fry a crisp delight with a soft and tantalizing center. When you let the fries sit too long, moisture migrates out from the center to the surface, softening it. When you microwave the already-compromised fries, the heat and steam demolish what’s left of their former rigor, and they become limp as a speed-curl in Houston. Note: a truly well-browned french fry will stand up to aging, and even microwaving, better than the fast-food standard. Alas, the spud-spawn of McDonald’s is merely blond, and its rigor is ephemeral as Bob Dole’s (pre-Viagra). ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [June 22, 2003, 5:31am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/10 "2003-06-22T05:31:29Z")
Of course it showed up twice. It’s _reheated_. [sub]farking hamster[/sub] ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [June 22, 2003, 5:38am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/11 "2003-06-22T05:38:26Z")
Of course it showed up twice. It’s _reheated_. [sub]farking hamster[/sub] ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [June 22, 2003, 12:20pm UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/12 "2003-06-22T12:20:22Z")
Hey, consider potato sandwiches, and forget that they used to be French Fries. I make them (potato sandwiches) almost every day at work from my leftover Outback cheese fries. Been doing it for quite a while. ---
**Author:** ![vasyachkin](https://avatars.discourse-cdn.com/v4/letter/v/c5a1d2/32.png) [@vasyachkin](https://boards.straightdope.com/u/vasyachkin)\ **Post date:** [June 25, 2003, 7:42am UTC](https://boards.straightdope.com/t/why-cant-fries-be-microwaved/183524/13 "2003-06-25T07:42:27Z")
fries are not that good for you, you know ? if they also taste like sh1t then just throw them away.