[HN Gopher] Microwaves: A Haven for Bacterial Diversity
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Microwaves: A Haven for Bacterial Diversity
Author : rbanffy
Score : 51 points
Date : 2024-08-22 07:03 UTC (2 days ago)
(HTM) web link (tecscience.tec.mx)
(TXT) w3m dump (tecscience.tec.mx)
| galdosdi wrote:
| Because microwaves don't heat matter. They heat* H2O molecules.
| This one weird fact is responsible for all of the weird
| differences between how they cook and how other more classic
| cooking methods work.
|
| We're taught that heating has three styles: convection,
| conduction, radiation. But AFAIK, microwaving is a fourth and
| distinct style.
|
| *: Even more specifically, they add rotational momentum to these
| molecules, which is not the same as heat, but gradually turns
| into heat (which is translational momentum) as they knock around.
| This, in addition to the fact that only the water is being
| heated, and that the microwave waves touch the food in an uneven
| pattern even if mitigated by a rotating platter, is why stirring
| or waiting or using "low power" (dithered) is an important part
| of microwave recipes, as well as why high moisture foods or
| intentional steaming works so much better in it
| firesteelrain wrote:
| Microwaves also affect other polar molecules and ions in food,
| not just water.
|
| This excitation leads to the generation of heat, which is then
| transferred through the food via conduction.
|
| Microwaving is indeed considered a form of dielectric heating,
| which is a subtype of radiation. It's distinct from conduction,
| convection, and traditional infrared radiation but still falls
| under the broader category of electromagnetic radiation-based
| heating.
| bsder wrote:
| > Microwaves also affect other polar molecules and ions in
| food, not just water.
|
| So why does sugar seem to heat so preferentially?
|
| I always found that microwaving any dish with a "syrup" made
| it the temperature of hot lava while the rest of the dish was
| still cold.
| sadhorse wrote:
| Microwave heating is not a fourth form of heat transfer as it
| name implies: microwave radiation. Yes, the heat is not being
| radiated by a thermal source of microwaves, but it is radiation
| being absorbed. Hence radiation is the mechanism.
|
| Rotational momentum is also heat as it is kinect energy related
| to movement, linear or not.
| galdosdi wrote:
| I'm speaking from a practical cooking perspective, not a
| technical physics perspective. The radiation from flames or
| the sun affects food very differently than microwaves do.
|
| For the same reason, I probably messed up other physics
| technicalities. It would have been nice if I added a caveat I
| guess, but so it goes. My mental model may be simpler than
| the truth, but it's a lot better for achieving practical
| results in the kitchen than nothing than "microwaves heat
| stuff up fast", which is what I had before and is a really
| shit model that fails to explain most of their odd behavior.
| HPsquared wrote:
| I suppose there's nothing stopping other forms of radiation
| like the visible spectrum. How about intense blue light? Could
| it penetrate better than microwaves?
| datameta wrote:
| Due to the higher frequency it wouldn't penetrate as well.
| But it is fun to think about the other EM sources used for
| cooking.
| Symmetry wrote:
| >According to the researchers, the findings underscore the
| importance of regularly cleaning microwaves to reduce potential
| health risks, particularly in environments where food is handled.
|
| Does that follow? I'd expect that as organisms adapt to
| environments that diverge further from the inside of your body
| they also become less dangerous, all things being equal. But then
| again I'd never heard the idea that microwaves are sterile inside
| and given the standing waves inside I would have dismissed it.
| creesch wrote:
| I am also wondering how resilient these organisms are in the
| food matter we are heating up once it is heated up to certain
| temperatures. I guess that also means I am wondering how much
| of these organisms are airborne or are just living on the
| surfaces of the microwave without ever coming into contact with
| my food.
|
| Having said that, one thing I regularly do is just place a bowl
| of water in the microwave with a bit of lemon juice (optional).
| Put it on for a very long time, so that is boiling for several
| minutes. Then wipe off the surfaces.
| throwup238 wrote:
| _> I am also wondering how resilient these organisms are in
| the food matter we are heating up once it is heated up to
| certain temperatures._
|
| I can't find the FDA food safety table right now but IIRC 12
| minutes at 140F, 1 minute at 165F, or less than 10 seconds at
| 185F is enough to kill off everything except endospores.
| adrianN wrote:
| Unless we have data that shows that people get sick from
| unclean microwaves I don't think you can conclude that they
| pose a health risk, no matter what bacteria you find inside.
| charlie0 wrote:
| Because so many people don't have the common sense to cover their
| food when they heat it up. A microwave is the worst thing to have
| in a college dorm. Guaranteed filth to be covering the inside.
|
| It also doesn't help the default power is set to 100%, causing
| volcanic like explosion of anything with high amounts of
| moisture, like tomato sauce. God save your tongue on taking a
| bite out of a Hot Pocket that's been in there too long. You swear
| there's lava in the thing.
|
| People just don't really know how to use microwaves.
| the__alchemist wrote:
| I blame the UI. IMO should be two knobs and a button. (Maybe
| you just push one of the knobs instead of the button)
| andrewshadura wrote:
| WDYM, but it _is_ two knobs and a button?
| airstrike wrote:
| My microwaves have no knobs
| the__alchemist wrote:
| Every one I've used looks like a blown-up calculator watch
| from the 80s.
| adrian_b wrote:
| Two rotary knobs for selecting power and duration and two
| push buttons for start and stop.
|
| Actually a third push button is also required, for storing
| a power+duration pair, when you want to have multiple
| segments where different powers are used.
|
| When using a microwave oven for cooking, not just for
| reheating, it is very common to use a high power for a
| short time, then one or two decreasing power levels
| sufficient to just preserve the current temperature, in
| order to avoid making a mess in the oven, due to violent
| boiling or high pressure steam generation.
| CatWChainsaw wrote:
| Knobs seem to be common on European microwaves. NA
| microwaves have all sorts of granular settings.
| charlie0 wrote:
| Yes, something like changing the power levels normally
| require pressing of multiple buttons. Many menus and options
| are also hidden that way. Unfortunately, the true potential
| of a microwave is locked away. Pretty much everyone I know
| just hits the 30 second button and is content with super hot
| or unevenly heated food.
| KineticLensman wrote:
| Presumably Duration, Power and Start/Stop. My NEF microwave
| has a Duration dial, 6 different power buttons (presets for
| 900, 600, 300, etc) and separate Start and Stop buttons. Oh,
| and another small button for forcing the Duration dial into a
| clock setting mode (to set the time-of-day display which is
| the default when the thing isn't heating).
|
| Works okay, quite intuitive, entirely used to it now.
|
| Just don't get me started on the controls for my induction
| hob
| exe34 wrote:
| yes! mine's like that, two knobs: one for how hot and the
| other is for how long. it's the dumbest one I could find and
| I'm never buying one with WiFi, thank you very much!
| adrianmonk wrote:
| IMO, for prepackaged foods like frozen dinners, the UI should
| be that you put the food in the oven and close the door, and
| the microwave figures out the rest. (Of course there would
| also be manual controls available.)
|
| The simplest way would be with a barcode on the plastic food
| tray. The barcode would contain the actual cooking
| instructions so that there's no internet dependency.
| sroussey wrote:
| My Tovala oven does this (you scan before you put in),
| though it uses steam and broiler not microwaves.
| geerlingguy wrote:
| But each food company would patent their own barcode
| retrieval system and put it behind a subscription, only
| $12.99 for the plan for foods with ads, $24.99 without!
| hyperdimension wrote:
| Juicero vibes here...
|
| (Good idea, though)
| rebuilder wrote:
| Two knobs will do. The timer knob can be used to stop the
| microwave and it starts once the timer is set and the door is
| closed.
| formerly_proven wrote:
| > People just don't really know how to use microwaves.
|
| Usually don't care, not don't know.
| HPsquared wrote:
| The two factors mutually reinforce each other.
| overstay8930 wrote:
| Most microwaves are terrible too, good microwaves are much more
| expensive so nobody buys them, but they can cook much more
| intelligently with higher quality parts.
| goda90 wrote:
| I've been dreaming of buying an inverter microwave(the
| inverter allows it to put out lower intensity microwaves to
| achieve lower power levels instead of just turning them on
| and off entirely like most microwave ovens), but for some
| reason the market for them is tiny. The kind I need, over-
| the-range inverter microwaves with ventilation, isn't even
| sold in the US. Strangely enough it is sold in Canada, which
| has the same electrical outlets. I might do a road trip to
| buy a microwave...
| geerlingguy wrote:
| We've had a Panasonic for a few years, and it's still weird
| (but good) hearing it running continuously on low power
| levels, versus the other microwaves that switch on and off
| for periods of time below 100%
| Brian_K_White wrote:
| I've never heard of this and it sounds great. Thanks for
| the heads up.
| Brian_K_White wrote:
| The only purpose a microwave serves in the first place is to
| heat as quickly as possible, and coffee and popcorn and hot
| pockets etc are not made any better by going slower. It is
| perfectly reasonable for the default to be 100%.
|
| It doesn't matter that you can produce a nicer result by going
| slower. You can also produce a nicer result by using a regular
| oven and fresh ingredients.
|
| The defined purpose of a microwave is to serve a different
| priority. A microwave with any other default is a dull saw
| blade.
| abeppu wrote:
| Time for a combined microwave oven / UV sterilizer to enter the
| market?
| dukeofdoom wrote:
| Sound like million dollar idea buddy
| CatWChainsaw wrote:
| Engineering or sales?
| roughly wrote:
| Everywhere is a haven for bacterial diversity. Bacteria outnumber
| human cells in your body 10:1.
| postalrat wrote:
| What harm is this causing? Are people getting sick?
| OutOfHere wrote:
| IMHO the harm is more likely from lids that are reused to cover
| food. If these lids are not routinely dishwashed like other
| utensils are, then by extension, they are likely to harbor
| bacteria and maybe even risk passing some into food. These lids
| are a lot closer to the food than the walls of the microwave.
| Indeed this could make people sick even if the microwave itself
| doesn't. Dishwashing the lid is paramount.
| Brian_K_White wrote:
| That is a theory or hypothesis, but the question is, does
| this theoretical harm actually exist? Are there actually
| significant numbers of people harmed by this mechanism? It
| might be but they don't show that.
| OutOfHere wrote:
| I don't know, but with an unclean lid, the potential is
| extreme. The lid accumulates water droplets that can easily
| drop back into the food with the bacteria included.
| shaneofalltrad wrote:
| I once had a baby spider living in the bottom corner of my
| microwave that I used about 5 or so times before it finally died.
| That's when I realized my understandings of microwaves was a bit
| cold in the edges.
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