Unoffical empeg BBS

Quick Links: Empeg FAQ | RioCar.Org | Hijack | BigDisk Builder | jEmplode | emphatic
Repairs: Repairs

Topic Options
#284677 - 20/07/2006 23:20 Microwave Oven Safety
tanstaafl.
carpal tunnel

Registered: 08/07/1999
Posts: 5543
Loc: Ajijic, Mexico
An acquaintance tried to convince me that microwave ovens caused unhealthy changes in the food that they heat. Maybe so. Maybe not.

But when he told me that plants watered with microwaved water would not grow, I became very skeptical. He invited me to perform the simple experiment of growing two plants from the same packet of seeds, one of them watered with water boiled on a conventional stove, the other with water heated by a microwave oven. Of course the water is allowed to cool before being applied to the plants.

I read of one experiment that supports this idea, but it was not scientifically run, no double-blind (or even single blind) methodology, and was a 6th grade science project. Perhaps microwaving leached contaminants out of the plastic container, or perhaps contaminants already present in the water might have been adversely affected by microwaves, or perhaps the experiment was never run at all and the results were made up, or ??

Does anybody have any insight into this idea? I remain highly skeptical, but am tempted to repeat the experiment myself.

tanstaafl.
_________________________
"There Ain't No Such Thing As A Free Lunch"

Top
#284678 - 21/07/2006 00:40 Re: Microwave Oven Safety [Re: tanstaafl.]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
While it's vaguely possible that microwaves could damage foods in ways we don't know about yet, the notion that water can be changed by a microwave is complete hogwash. There are very few things that can be done to water. You can contaminate it or decontaminate it. You can change it from ice to water to steam. You can turn it into oxygen and hydrogen. That's it.

I'd guess that, assuming that the experiment wasn't contaminated in some way, which I'm inclined to say it was, the microwave likely had an effect on preexisting contaminants in the water. Given how much easier it is to boil water in a microwave than on a stove, I bet the contaminants were simply more concentrated in the microwaved water. A good way to test that would be to start with distilled water.

I also bet the same vessel was not used to contain both doses of water. The only thing I can think of that can perform on the stovetop and the microwave would be Corningware, but I bet metal was used on the stovetop and either glass or plastic in the microwave.

I'd try it, but I'm terrible at growing plants, and, well, I've got better things to do than spend that much time disproving crackpot theories.
_________________________
Bitt Faulk

Top
#284679 - 21/07/2006 01:38 Re: Microwave Oven Safety [Re: tanstaafl.]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31578
Loc: Seattle, WA
Quote:
He invited me to perform the simple experiment of growing two plants


Stop right there. That's not a proper experiment. When you're dealing with living things, you need very large sample sizes.

By inviting you to perform the experiment yourself with only two plants, he's making it a 50-50 crap shoot as to whether he gets his desired results or not.


Quote:
I read of one experiment that supports this idea, but it was not scientifically run, no double-blind (or even single blind) methodology


Even if you could do it double blind, there's still the problem of variance in all living things. You could buy two potted plants and water them exactly the same, and one of them is gonna do better than the other no matter what.
_________________________
Tony Fabris

Top
#284680 - 21/07/2006 07:41 Re: Microwave Oven Safety [Re: tfabris]
g_attrill
old hand

Registered: 14/04/2002
Posts: 1172
Loc: Hants, UK
Quote:

Even if you could do it double blind, there's still the problem of variance in all living things. You could buy two potted plants and water them exactly the same, and one of them is gonna do better than the other no matter what.


We currently have four plants at home grown from some seeds collected from a plant elsewhere. Three are about 12" tall and equally well developed and a dark green colour. One is about 3" tall and a much lighter green.

I am no scientist or plant expert, but if I was going to do such an experiment I would probably want to use ten or so in total, and ensure that each plant had an identical amount of water and that they were planted the same - ie. seed central, the same way up etc. I am sure there are lots more things to think about, for example a group of plants will get different amounts of light and heat, so you would either need to alternate the group or move them around.

On the subject of microwaves themselves - a family friend mentioned the scare story and said their daughter showed them a large number of printouts and after reading it they got rid of their microwave. I did some searching and found all the various sites and concluded it was a load of hokum. I was suprised that they believed it - the daughter is an analyst for IBM and pretty smart by all accounts.

Gareth

Top
#284681 - 21/07/2006 10:01 Re: Microwave Oven Safety [Re: tanstaafl.]
Roger
carpal tunnel

Registered: 18/01/2000
Posts: 5682
Loc: London, UK
Quote:
But when he told me that plants watered with microwaved water


Why would you be boiling the water for your plants, anyway?

We don't have a microwave, mainly because we just don't have room in the kitchen (we don't have a dishwasher either, for the same reason), and I can't say I'm missing it particularly.
_________________________
-- roger

Top
#284682 - 21/07/2006 10:04 Re: Microwave Oven Safety [Re: tanstaafl.]
sein
old hand

Registered: 07/01/2005
Posts: 893
Loc: Sector ZZ9pZa
I don't have any real idea whether Microwaves are actually dangerous.

But I do think they can alter the taste of food in a very subtle way. I really think a glass of water that has been Microwaved for a few seconds tastes different to water that has been in the Kettle for a few seconds.

I haven't met anyone who agrees with me yet. Am I crazy?

During Ramadan when we're fasting we get up before dawn for a bit of breakfast that will see us through the day. In the winter mornings the water from the tap is very cold, so this is how I've been testing my theory
_________________________
Hussein

Top
#284683 - 21/07/2006 10:07 Re: Microwave Oven Safety [Re: sein]
tahir
pooh-bah

Registered: 27/02/2004
Posts: 1900
Loc: London
Quote:
In the winter mornings the water from the tap is very cold, so this is how I've been testing my theory


Did wonder why exactly you've been nuking your h2o

Top
#284684 - 21/07/2006 10:31 Re: Microwave Oven Safety [Re: tahir]
sein
old hand

Registered: 07/01/2005
Posts: 893
Loc: Sector ZZ9pZa
Quote:
Did wonder why exactly you've been nuking your h2o

lol, yeah I thought I'd add the bit at the end since heating up water before drinking is something my grandparents did!
_________________________
Hussein

Top
#284685 - 21/07/2006 10:37 Re: Microwave Oven Safety [Re: sein]
Roger
carpal tunnel

Registered: 18/01/2000
Posts: 5682
Loc: London, UK
Quote:
I really think a glass of water that has been Microwaved for a few seconds tastes different to water that has been in the Kettle for a few seconds.


This is probably down to limescale in the kettle.
_________________________
-- roger

Top
#284686 - 21/07/2006 10:42 Re: Microwave Oven Safety [Re: Roger]
sein
old hand

Registered: 07/01/2005
Posts: 893
Loc: Sector ZZ9pZa
Quote:
This is probably down to limescale in the kettle.

Not entirely convinced. The kettle water tastes 'Normal', and the microwave water tastes 'Different'. Thinking along the same lines though... it is possible that the inside of my Microwave needs a clean!
_________________________
Hussein

Top
#284687 - 21/07/2006 10:47 Re: Microwave Oven Safety [Re: sein]
Dignan
carpal tunnel

Registered: 08/03/2000
Posts: 12318
Loc: Sterling, VA
Quote:
But I do think they can alter the taste of food in a very subtle way. I really think a glass of water that has been Microwaved for a few seconds tastes different to water that has been in the Kettle for a few seconds.

I think it's like Bitt said, you're probably heating the water in different containers, which I'm sure affects its taste.

Myself, I've never thought twice about microwaved water or any liquids. Then again, I never heat water on the stove so I don't really know what that that tastes like. I'm guessing it tastes like water.

I prefer the third method. I have an instant-hot faucet in my kitchen. Steaming hot water whenever I need it!
_________________________
Matt

Top
#284688 - 21/07/2006 11:01 Re: Microwave Oven Safety [Re: sein]
tahir
pooh-bah

Registered: 27/02/2004
Posts: 1900
Loc: London
Quote:
heating up water before drinking is something my grandparents did!


My dad's flu remedy used to be hot lucozade, in the days that it used to come in that transparent yellow wrapper.

Top
#284689 - 21/07/2006 11:06 Re: Microwave Oven Safety [Re: wfaulk]
pedrohoon
enthusiast

Registered: 06/08/2002
Posts: 333
Loc: The Pilbara, Western Australia
Quote:
There are very few things that can be done to water. You can contaminate it or decontaminate it. You can change it from ice to water to steam. You can turn it into oxygen and hydrogen. That's it.



Well you can change it into various forms of heavy water, but whether a microwave oven will do that is doubtful.
_________________________
Peter.

"I spent 90% of my money on women, drink and fast cars. The rest I wasted." - George Best

Top
#284690 - 21/07/2006 11:48 Re: Microwave Oven Safety [Re: pedrohoon]
peter
carpal tunnel

Registered: 13/07/2000
Posts: 4174
Loc: Cambridge, England
Quote:
Well you can change it into various forms of heavy water, but whether a microwave oven will do that is doubtful.

"Doubtful"? If you can fuse hydrogen-1 to deuterium at microwave oven temperatures, I'm sure a Nobel prize awaits... except of course they're not awarded posthumously...

Peter

Top
#284691 - 21/07/2006 12:22 Re: Microwave Oven Safety [Re: peter]
pedrohoon
enthusiast

Registered: 06/08/2002
Posts: 333
Loc: The Pilbara, Western Australia
Quote:
at microwave oven temperatures




Yeah, for fusion you might need higher temps .

However if a microwave can reach 130°C, this may work .

j/k

Realistically, to get back to Bitt's point, a microwave probably won't alter the water in any way other than heating.
_________________________
Peter.

"I spent 90% of my money on women, drink and fast cars. The rest I wasted." - George Best

Top
#284692 - 21/07/2006 12:38 Re: Microwave Oven Safety [Re: sein]
boxer
pooh-bah

Registered: 16/04/2002
Posts: 2011
Loc: Yorkshire UK
Quote:
But I do think they can alter the taste of food in a very subtle way.

(1) Scrambled egg is the only thing I know that tastes much better out of a microwave, than cooked in a pan on a stove: Many things taste just as good.
(2) Kippers taste as good when cling filmed on a plate and microwaved, the advantage being it takes a third of the time and doesn't stink the house out.
(3) A patent microwave egg boiler is much more trouble than sticking them in a pan on the gas.

There you have my entire repertoire: I only do breakfast.

I never understand this snobbish reluctance to accept microwaves as a perfectly good way of cooking: When civilization moved from a pot dangling from a wooden tripod over an open fire to using a stove, did the cry go up: "Yes, but it's not real cooking".
_________________________
Politics and Ideology: Not my bag

Top
#284693 - 21/07/2006 12:52 Re: Microwave Oven Safety [Re: boxer]
tahir
pooh-bah

Registered: 27/02/2004
Posts: 1900
Loc: London
Quote:
When civilization moved from a pot dangling from a wooden tripod over an open fire to using a stove, did the cry go up: "Yes, but it's not real cooking".


No, but I think the event predated the arrival of food critics.

Top
#284694 - 21/07/2006 12:59 Re: Microwave Oven Safety [Re: boxer]
andy
carpal tunnel

Registered: 10/06/1999
Posts: 5914
Loc: Wivenhoe, Essex, UK
I find the microwave most useful for steaming veg (in one of those microwave steamers) and making porrige.

A combined microwave/convection oven is great for jacket potatoes. Ours does convincing jacket potatoes in 30 minutes, nice and crispy because it gives the potatoes a blast with the microwave while it waits for the oven side to walm up and crispy them off.
_________________________
Remind me to change my signature to something more interesting someday

Top
#284695 - 21/07/2006 13:07 Re: Microwave Oven Safety [Re: andy]
tahir
pooh-bah

Registered: 27/02/2004
Posts: 1900
Loc: London
I do miss our old combi, used to be great for jackets, got a dodgy sanyo now, crap at jackets.

Top
#284696 - 21/07/2006 13:09 Re: Microwave Oven Safety [Re: boxer]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
Microwaves are looked down upon because they do a lousy job cooking a great many things, especially meats, which is one of the things they were initially marketed for. Remember when they advertised that you could cook a turkey or a roast in much less time? For thick things they work incredibly poorly since they largely can't heat things much past the boiling point of water (water is a large portion of the molecules in food that microwaves can successfully heat) and they only penetrate the meat by a few inches. That means that it's possible to cook a steak, but cooking a roast means you'd have to rely on intra-food conduction to cook the center, and since that sort of conduction takes a long time during which you have to continue pushing heat into the food, the utility of using a microwave in the first place is lost.

At the same time, you cannot form any sort of browning on a steak due to the low temperatures involved, and that's, at best, unappealing, and, at worst, just tastes lousy. Also, since the microwaves do penetrate beyond the surface somewhat, you have a hard time getting the outside done while leaving the inside medium-rare.

Also, and I don't have much to back this up, my personal experience is that microwaves make meat rubbery.

But they're great for reheating, as you seldom want to reheat past 212F/100C anyway.

As to your points: You must like rubbery eggs. I've had microwaved scrambled eggs and they're terrible. Maybe you add a lot of milk or cream? I have no experience with kippers at all, but they're thin and require low temperature cooking, so I can see how that might work well. And, you're right; it's hardly difficult to boil some water on the stove, and the microwave might end up cooking the egg via the microwaves instead of from the conduction of the boiling water, which probably wouldn't work well.
_________________________
Bitt Faulk

Top
#284697 - 21/07/2006 13:26 Re: Microwave Oven Safety [Re: wfaulk]
boxer
pooh-bah

Registered: 16/04/2002
Posts: 2011
Loc: Yorkshire UK
Quote:
a lot of milk

A reasonable amount, and they are certainly not rubbery, the trick is to take them out and stir them half way.
_________________________
Politics and Ideology: Not my bag

Top
#284698 - 21/07/2006 15:22 Re: Microwave Oven Safety [Re: wfaulk]
tanstaafl.
carpal tunnel

Registered: 08/07/1999
Posts: 5543
Loc: Ajijic, Mexico
cooking a roast means you'd have to rely on intra-food conduction to cook the center, and since that sort of conduction takes a long time during which you have to continue pushing heat into the food, the utility of using a microwave in the first place is lost.

I'm glad to see you are not perpetuating the [erroneous] myth that microwave ovens cook "...from the inside out."

But, if a mocrowave oven has to "...rely on intra-food conduction to cook the center...", then what does a conventional oven rely on? Seems to me it heats the outside, just like a microwave oven, and the heat has to migrate towards the center the same way.

Perhaps it is a function of the higher external temperatures provided by a conventional oven?

tanstaafl.
_________________________
"There Ain't No Such Thing As A Free Lunch"

Top
#284699 - 21/07/2006 15:48 Re: Microwave Oven Safety [Re: tanstaafl.]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
My point is that you have to apply heat for the same amount of time (if not longer due to the lower temperatures that can be achieved by a microwave), so why waste your time with the microwave in the first place? It's probably going to end up taking just as long and using more energy, and the lack of the high temperatures on the outside or any radiative heating means that you aren't going to get any tasty browning. (Plus my anecdotal rubberiness factor.)

On the other hand, there have been times in history when browned meat was found to be gauche, which is the history behind wrapping a filet in bacon; originally it would have been some other cheap meat wrapped around the entire tenderloin roast and discarded (to the servants, most likely) before serving.

There are other concerns, too, like the fact that it's hard to control heating in a microwave, since it there is only one power (that can be cycled on and off on lower power settings on your micorwave oven) and the heat generated depends largely on the specific interactions with the material in the oven.
_________________________
Bitt Faulk

Top
#284700 - 21/07/2006 19:38 Re: Microwave Oven Safety [Re: peter]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
Zandr was telling me about a rather expensive practical joke involving buying heavy water (you can get it somewhere online, I hear) and making icecubes that sink in normal water....

Of course, as the heavy icecubes melt, they'll then float on the heavy water and start floating off the bottom of the glass. I think.

Hugo

Top
#284701 - 21/07/2006 19:48 Re: Microwave Oven Safety [Re: altman]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
_________________________
Bitt Faulk

Top
#284702 - 22/07/2006 10:56 Re: Microwave Oven Safety [Re: wfaulk]
pedrohoon
enthusiast

Registered: 06/08/2002
Posts: 333
Loc: The Pilbara, Western Australia
Quote:

There are other concerns, too, like the fact that it's hard to control heating in a microwave, since it there is only one power (that can be cycled on and off on lower power settings on your micorwave oven) and the heat generated depends largely on the specific interactions with the material in the oven.


There are now Inverter microwaves available, although they still don't brown food.
_________________________
Peter.

"I spent 90% of my money on women, drink and fast cars. The rest I wasted." - George Best

Top
#284703 - 22/07/2006 15:53 Re: Microwave Oven Safety [Re: pedrohoon]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31578
Loc: Seattle, WA
Interesting! I didn't know such a kind of microwave existed.
_________________________
Tony Fabris

Top
#284704 - 24/07/2006 05:34 Re: Microwave Oven Safety [Re: tfabris]
adavidw
addict

Registered: 10/11/2000
Posts: 497
Loc: Utah, USA
I've got one. $99 at Costco. It works wonders for things like melting or defrosting. A traditional microwave at a low setting will cook the outsides of things while the inside is still frozen because even though it might only be powered for 2 out of every ten seconds, it's at 100% for those 2 seconds. When I would melt a big hunk of butter in my old microwave, I'd get really annoyed when I'd see the butter boil for five seconds, then just spin for five seconds, and so on.

Now with my new microwave, I can get really even melting or reheating, just at the expense of some time. I wouldn't consider buying a microwave without this feature.
_________________________
-Aaron

Top