Usually my morning starts with a measure of naturally-dechlorinated water emptied into a kettle, set over flame, brought to a boil, and poured over coffee grounds.

This morning I boiled the water in a Pyrex cup within the microwave. It is a clean device absent of odor, no Hot Pockets or anything remotely similar cooked within.

So the water sails through the coffee and the experience is a little different. Is there something different about nuked water I missed in school?

Is someone going to tell me the H2O molecule loses it's 3rd level electron or gains this and that while being nuked, and that affects flavor? I remember when microwave ovens came out; real chefs refused to use them. I do service work for a college bar and their large kitchen does not have a microwave oven in it.

Not a scientist nor did I stay in a holiday inn express last night however, I've found nuked food and water do not retain their heat nearly as well as stovetop heated items. Temperature is often a key component in coffee or certain teas so that may ave thrown things out of wack?

Microwaves don't heat water as evenly as a pot on the stove. The stove's heating element heats the bottom of the water column which causes that water to rise and be replaced by the cooler water; a convection process that continues until all of the water hits boiling point.

A microwave only heats the water where the microwaves hit the water which is a somewhat random process. The heated water doesn't really mix with the rest of the water before localized hot spots start to boil.

You can test this with an instant read thermometer. Heat water in a pot to boil and measure the temp. Heat water in the microwave to a boil, give it a stir, and measure the temp.

He's not talking about the temp, he's asking about taste. My guess is that when using the kettle, the heated metal transfers some chemical to the water. Kind of like getting g a metal taste to your water.

Water at 212F is water at 212F. It doesn't know what added the heat.

I think what you may be seeing is that maybe the visual cues of boiling in a microwave make it appear that the water is all at the boiling point when it's not. I think if you 'nuked the crap out of it' then it'd be more likely to taste the same as the water from a kettle.

Detailed, seat of the pants rationale below:
**********hypothesis start
Boiling is a bunch of things all wrapped into one. (I loved my heat/mass transfer course in Mech E. )

The act of boiling mixes the living shit (technical term here) out of the water. The bubbles rising, the hottest water rising and the cooler water at the top (cooled by the evaporation there) falling - so lots of convection happening in the water by this motion as the boiling starts.

After this has happened for long enough (technical term) the temperature gets pretty uniform - it's then all at the boiling point and the added heat just converts water to steam, instead of heating the water.

In a kettle, it takes longer to boil because the convection forces all the water to be at the boiling point before any boiling happens (first approximation - ignoring the small-scale boiling at the bottom when things first get started.)

I think the hot spots in the microwave may be making some of the water flash boil when the rest isn't at the boiling point. So you get the visual cue 'it's boiling' but some of the water's not actually at the boiling point.
**********hypothesis end

Be VERY careful with microwave boiling; because it does not get the point of contact heat from a range top, water can become superheated but just appear steamy. It can be full of pent up energy and the slightest jostling can cause it to erupt suddenly, causing terrible burns.

https://m.youtube.com/watch?v=FsjuM1kR7-w

Be careful when boiling water in a microwave. I have heard that the water can reach temperatures above boiling point with out it looking like it is boiling.
When the water is removed from the microwave or disturbed in any way in the microwave after heating it explodes and can injure someone.
If my memory serves me correctly I saw it on a cooking show called Good Eats with Alton Brown.

quote:

Originally posted by Shaql:
He's not talking about the temp, he's asking about taste. My guess is that when using the kettle, the heated metal transfers some chemical to the water. Kind of like getting g a metal taste to your water.

The taste after pouring the heated water over coffee grounds? As in, if the microwaved water isn't the same temperature as the pot boiled water when poured over the coffee grounds the result would taste different?

Here's an idea from Smithsonian Magazine: The water was probably at a different temperature than you're used to via boiling in the pot (212) so the coffee was processed differently and tasted different.

quote:

Why Microwaving Water for Tea Is a Bad Idea

https://www.smithsonianmag.com...a-bad-idea-97452679/

Water at 212 deg. is water at 212 deg.- it's the same. There's also Superheating- The microwave can make the water hotter than its boiling point without any visual sign of boiling.

https://en.wikipedia.org/wiki/Superheating

^^^

I have always found that using water boiled in a microwave vs. conventionally for tea results in the release of very fine bubbles (i.e. foam) when sugar or artificial sweetener is added to the tea, post brew.

No such bubbles when adding the same sweeteners to conventionally boiled tea, but always so with microwave boiled.

Related question.
I think boiling water changes the taste, sort of a flatter taste that I don't like. Admittedly, maybe just imagined, but for that reason I stop short of boiling the water for my sweet tea. Anyone else think water taste better if not boiled? Is there any scientific reason for this or am I just nuts?

The taste of water doesn't come from the water. Could it be possible that in a microwave, some of the minerals in the water get superheated and change in some way? Or in the metal tea kettle interact with the metal and change in some way?

Microwaved water is changed to pure energy and then changed back into water. The result of the change is water that is unhappy, and unhappy water is hotter. And nobody likes unhappy coffee.

-Bob Ross

quote:

Originally posted by cparktd:
I think boiling water changes the taste, sort of a flatter taste that I don't like.

After you boil the water, get a like-sized container out of your cabinet and pour the water back and forth between the two containers a few times. This will reintroduce into the water some of the oxygen which was lost during boiling.

Aeriating the water will rid it of its flat taste.

Water can easily become superheated in a microwave oven. I doubt that it changes the flavor of the water but it can splatter and burn you or a least make a mess. You can avoid the superheating by placing something inert in the water to promote 'nucleation'. I use a small marble chip (sold for placing in the bottom of flower pots).

These beakers from American Science and Surplus:



One minute boils ~150ml of water in my microwave. You can easily pull it out before just before boiling for delicately flavored teas.

quote:

Originally posted by parabellum:

Aeriating the water will rid it of its flat taste.

So I'm not crazy! The taste does change, but an easy solution it seems!
Thanks.

quote:

Originally posted by cparktd:

quote:

Originally posted by parabellum:

Aeriating the water will rid it of its flat taste.

So I'm not crazy! The taste does change, but an easy solution it seems!
Thanks.

Well, you're not *wrong*.

Here’s my take which is an amalgamation of previous replies.

The cause in the difference could be driven by uneven differing temperatures in parts of the microwaved water. Another cause is the presence of gases still in the microwaved water.

First, how do you boil the water in the microwave? Do you wait until it literally boils? If it’s literally boiling, you’ve heated parts of it over 212 degrees. If it’s only by time, then some parts haven’t reached 212 degrees. The reason for this is in a microwave and you put the water in the center, the water molecules get heated first and not much convection movement is happening. This sometimes results in superheated water in the middle of a microwaved cup of water that it exploded if you put coffee or sugar into it. On a stove, convection occurs and the water molecules are heated evenly from the bottom and when it boils, it’s uniformly hot. Coffee reacts differently to the temperature of the water. For French press that I use, recommended is less than boiling temperature.

Also, the different temperatures may still allow gas to be trapped in the areas of less than boiling and that may affect the taste.

OK, my take. In the microwave you contain the water in a glass or other non-metal vessel. On the stove you probably use a metal vessel. Water boiled in metal tastes different from water boiled in glass. Voila!

flashguy

quote:

Well, you're not *wrong*.