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Strange nettle reaction in Microwave!!!

Thelma McGowan

Joined: Jul 03, 2011
Posts: 170
Location: western Washington, Snohomish county--zone 8b
I would love to get some of you to try this....

I blanched some nettles and then dumped them in an ice water bath to use for later.

Then I wanted to have a few bites of nettle with some butter and I put a couple stems in the microwave to warm them up......
The Nettles actualy caught fire in the microwave...I am talking actual flames ans scorched stem.....weird!
so I tried another stem in the microwave and it caught fire to and part of the stem burst into flame
this all happened with in about 15 seconds....

I am going to try some raw nettle too....

HAve you ever put Nettles in the microwave What do you think is doing this.....I know there are a lot of minerals, and crystal structures, maybe the acid on leaves...But it seems to be isolated to the stems?? I would love to hear feed back to see if it is just my nettles.

There are no experts, Just people with more experience.
Isaac Hill

Joined: Feb 28, 2011
Posts: 354
Location: Beaver County, Pennsylvania (~ zone 6)
I think your first problem is using a microwave. Maybe the nettle knows how horrible they are and is trying to tell you something.

"To oppose something is to maintain it" -- Ursula LeGuin
paul wheaton

Joined: Apr 01, 2005
Posts: 17054
Location: missoula, montana (zone 4)

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Tyler Ludens

Joined: Jun 25, 2010
Posts: 5344
Location: Central Texas USA Latitude 30 Zone 8
I tend to agree with Isaac. I admit to a superstitious fear of microwaves. Other people have more scientific reasons for avoiding them, but mine is purely fear-based. :p

Idle dreamer

Burra Maluca
Mother Tree

Joined: Apr 03, 2010
Posts: 6966
Location: Portugal Zone 9 Mediterranean Climate
I wonder if it's anything to do with the needles? I think they are made of some form of silica, like a natural glass, and are hollow like a hypodermic needle. Could they be acting as some kind of lens? Or maybe the poison inside the needles overheats and then sets fire to the surrounding cells when the neeldes burst? Or something...

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Jocelyn Campbell

Joined: Nov 09, 2008
Posts: 3039
Location: Missoula, MT
Thelma, this is amazing. And Burra, you are so clever to come up with those deductions.

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Thelma McGowan

Joined: Jul 03, 2011
Posts: 170
Location: western Washington, Snohomish county--zone 8b
Here is the picture evidence from the forth nettle that I sacrificed to the Microwave. so far it has been consistently catching fire at the stem or leaf stem and just 1 spot on the plant......the leaves are just wilting. I look forward to trying this in the summer to see if it happens all over the plant. I suspect it is a small iron deposit, As I have read that they are high in iron and minerals...but it occured to me it might be a small bug inside the stem??

By The way.....The Nettles are definetly telling me something ;0)....I cut away the scorched part and put butter and salt on them, and they said "I am delicious"!

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Eric Thompson

Joined: Apr 23, 2011
Posts: 305
Location: Bothell, WA - USA
Like any good scientist, I struck out this morning to confirm Thelma's findings:
1. pick 3 fresh nettles, 4-8 inches tall, with full stem
2. Lay fresh on a plate and microwave on high
3. After 28 seconds, visible sparking erupts and smoke is coming off of the nettles
4. remove plate of nettles to a small cloud of smoke and observe burned areas on stems, just below the leaf junction - smallest stem burned the most

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Mike Underhill

Joined: Feb 12, 2012
Posts: 53
Location: N. Sac. Valley
I have come to distrust microwaves too, however, I think Thelma's nettles caught on fire because there was not enough matter to disperse the energy of the microwave. Put a cup of water in there with the nettles and I'll bet no fireworks.

I like this sort of thing.
Thelma McGowan

Joined: Jul 03, 2011
Posts: 170
Location: western Washington, Snohomish county--zone 8b
Eric--The strange part is the isolated areas in the stem that burn. The whole plant is not arcing and bursting into flames, so what do you think is causing the arc? Than you for confirming that I do not have some mutant Nettles....Very good scientific protocol :0)

Wow...this is proving to me that Nettles are even more amazing than I thought. I am certainly not trying to create hysteria regarding Microwaves or Nettles. I am not going to let a microwave incedent stop me from eating an ancient proven healthy food source.
Thelma McGowan

Joined: Jul 03, 2011
Posts: 170
Location: western Washington, Snohomish county--zone 8b
I tried a stem of nettle in a bowl of water---No Sparks
Then I tried the same stem of nettles on a plate with a small bowl of water---no sparks
Then I tried the same stem on a plate with no water source.....and it sparked!

I don't quite understand your science....but it seems to be the case :0)

FYI-----When cooked in the microwave the sting is not removed......:0(
Brenda Groth

Joined: Feb 01, 2009
Posts: 4433
Location: North Central Michigan
yikes pyrotechniques (sp)...when I "steam" greens I often steam them in those fancy pantsy stem in bags that I got free ..a few boxes of..and they work really well, I can just imagine an entire bag of them things blowing up my microwave..

right now I can't find nettles growing around here, I bought seed to plant some as they aren't very common here, but my seeds have not erupted yet.

not sure I dare try them in the stem in bag though..will let you know if i do..if I ever find any nettles.


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Matthew Nistico

Joined: Nov 20, 2010
Posts: 222
Location: Clemson, SC ("new" Zone 8a)
How fascinating. Who knew that cooking wild-crafted greens could be so entertaining?! Paul, are you paying attention to this - if flaming nettles aren't just begging to be the subject of your next video, I don't know what is! It could be the next YouTube sensation, LOL! : )

Blazing trails in disabled homesteading
Ken Peavey

Joined: Dec 21, 2009
Posts: 2523
Location: FL
I'm gonna put out a theory, you folks shoot it down...

Harmonic Resonance
I found some plants that may be nettles. I've yet to try them, not yet enough for a meal. I looked at the needles along the stem-The higher up the stem, the smaller the needles. I suspect this is due to growth. The lower needles have had more time to grow.

Going with Burra's notion that they are high in silica, and Thelma's notion about a high iron content, these materials would be sufficient to create a resonance chamber within the hollow needles. For this to occur, the needles would have to be the right size: too big or too small and the effect would be lost. Hence, with graduated needle sizes along the length of the stem, there would be a spot where the needle size would be just right, microwave resonance occurs, the needles overheat and asplode.

Water should act as a heat exchange medium, reducing the build up of heat. Until it dries out.

Occam's Razor says the simplest solution is probably the right one. I considered the bug theory, but Eric Thompson duplicated the results with no mention of bugs.

Seed the Mind, Harvest Ideas.
Duncan Dalby

Joined: Jan 22, 2012
Posts: 36
Location: England, Midlands.
The next thing to do is try some unrelated plant stems and see if the same thing happens. If not then it must be something to do with the make up of the nettle. If it does then it mite be something quite simple like one bit of the stem getting court in a hot spot in the microwave and trying out, once dry the next time it passes through the hotspot there's nothing to stop it bursting into flames. Either way I think I know one thing I'm going to be doing today :-p
Erica Wisner

Joined: Feb 10, 2009
Posts: 877
Location: Okanogan Highlands, Washington
Just for general info - I have used a microwave to dry other herbs (between sheets of paper towel), and I usually don't see any popping or charring. I have done this with other members of the mint family, like basil or oregano.

I have seen similar charring once maybe, but I don't remember what plant it was. Might have been nettle, might have been a brown paper bag of something else. I just figured it was the microwave, or a speck of dirt, or something. I think I had the tray unevenly loaded, so I just assumed it had stopped and overheated in one place.

I got some really weird browning and near-charring on lavender one time. I was trying to nuke it to get rid of some moths, but it was a disaster. Created a whole new, and much less pleasant, version of lavender's volatile oils. Had to trash that one, and air out the kitchen. It smelled odd for some time.

I believe nettle stings have a spiral shape - I don't know what material it is that holds the tension, but it's possible that it has weirdly conductive properties, or lensing properties like glass. I know spiral coils are commonly used to intensify electromagnetic fields e.g. coils in generators and electromagnets. This seems to support the idea that it's the stings that serve as a focus for the weird reaction. Maybe the spiral is helping create a focused electro-magnetic field in the right-sized sting?

The other thing lavender and nettle have in common is a fair amount of little pockets of oil or liquid in their structures. I think there might very well be a size where resonance is created, and it might be very close to the length of a lavender blossom or the thickness of a nettle stem. The holes in the microwave screen are supposed to be the right size to create interference / break up the wave structures, and stop the waves passing through. So I have always pictured microwaves as slightly larger than those holes, maybe 2-3 times larger / longer.

I would not be surprised if you can get a similar, focused charring out of most older microwaves, if you put a very small, or unevenly-shaped, unevenly-wetted material inside. Anything that conducts electricity unevenly may create focused overheating spots. Microwaves are designed to get things hot by jiggling the water up to steam velocities, so most microwave cookbooks say to put things in a cup or bowl of water for even cooking.

The best part of all this is, I don't own a microwave, so all of the above experiences happened as a guest in someone else's home. That's the main reason why I didn't repeat the experiments to see what was causing it!

oops... sorry...
let me tidy up the debris, I'm sure your kitchen will be fine after I leave...


Play with nature, make nifty stuff:
Duncan Dalby

Joined: Jan 22, 2012
Posts: 36
Location: England, Midlands.
I believe the microwaves used in microwave ovens are quite big. Somewhere between 10 and 20 cm. Thats what I've heard but also backed up with experience. When we bought our new microwave oven with a regular oven built in I tried baking a cake in it. Half way through for some reason it decided to switch from oven mode to microwave mode and cremated my cake. The interesting thing was that because the cake wasn't turning it didn't get heated evenly and when I cut the cake in half there was a lovely wave form with chard cake on one side and half cooked on the other. The wavelength was around 15cm as I remember.
Burra Maluca
Mother Tree

Joined: Apr 03, 2010
Posts: 6966
Location: Portugal Zone 9 Mediterranean Climate
I've had some ideas from facebook friends...

Dave said
Microwaves jiggle (nice technical term that ) all molecules. Thin metal will burn under the effect, as will just about anything else if the heat isn't carried away fast enough by conduction, convection, or radiation, and there is oxygen available.

And Alun said
Sounds very like what you can do with a grape. Cut a garpe almost in half so the two halves are connected by a bit of grape skin. Put that in the microwave for a few seconds and you'll get sparks. So probably not to do with the needles.

and then added
I've just done some googling. In the case of grapes, there are various pages mentioning that a grape prepared as above roughly forms a resonant antenna at the frequency used in a microwave oven (quarter wave at 2.45GHz is 30mm, so that sounds about right). Things that are resonant at a frequency can pick up a disproportionate amount of energy from whatever's jiggling at that frequency (think "opera singer breaking wine glass by hitting the right note").

All that sounds quite reasonable as an explanation of why the grape does what it does. I wonder if the gaps between leaf stalks on the stems are around 30mm?
Aschwin Wesselius

Joined: Apr 03, 2012
Posts: 7
Hi, this is my first reply on So forgive me if I break any unknown, undisclosed convention or anything.

I think the nettles are full of nitrogen. Nitrogen is very inflamable. I might be wrong, but it's my guess.
Thelma McGowan

Joined: Jul 03, 2011
Posts: 170
Location: western Washington, Snohomish county--zone 8b

And Alun said
Sounds very like what you can do with a grape. Cut a garpe almost in half so the two halves are connected by a bit of grape skin. Put that in the microwave for a few seconds and you'll get sparks. So probably not to do with the needles.

I tried the Grape did not flame but the little skin between the grape halves did scorch and turn black....hhmmm.

I think this has been the most motivating thread for people to find a patch of nettles!! hahaha
subject: Strange nettle reaction in Microwave!!!