Fitting kitchen extractor

[Harry Bloomfield]

now done with grandchildren in the microwave.

Is that not dangerous for the kids?

 

[amfisted]

There is normally not need for them to be bubbling furiously - a simmer is similar to a boil in temperature and allow a lid to be used. A hob fan which doesn't extract to outside is rather pointless.

It's normally me who "bubbles furiously", when I go to wash the dishes after the meal and find the surface of the hob covered in a sticky mess. And I agree that discharging fumes and steam to outside is by far the best option. In our last house we had a cooker hood that filtered and recirculated, and if it had been made of cheese it couldn't have been less effective.

 

[SUNRAY]

Is that not dangerous for the kids?

But at least I know where they are.

 

[FrodoOne]

It is strange that some seem to think that "boil" means to cause vigorous agitation in the water by the application of excess heat.
"Boiling" means only to maintain the temperature of the water at "boiling point" and (sometimes) to cause a little agitation during this process - to assist in keeping the Pasta, Rice Grains or whatever separate.
This might be described more accurately as "Simmering".

If one "boils" an egg, the vibration caused by vigorous boiling could be detrimental to the shell of the egg!

Any excess energy input causing water to vaporise into non-visible "steam" (and then condense into visible droplets of water) is usually a waste of energy.

While there may be recipe directions which recommend vigorous "boiling", I would question as to why this would be necessary.

 

[opps]

It is strange that some seem to think that "boil" means to cause vigorous agitation in the water by the application of excess heat.
"Boiling" means only to maintain the temperature of the water at "boiling point" and (sometimes) to cause a little agitation during this process - to assist in keeping the Pasta, Rice Grains or whatever separate.
This might be described more accurately as "Simmering".

If one "boils" an egg, the vibration caused by vigorous boiling could be detrimental to the shell of the egg!

Any excess energy input causing water to vaporise into non-visible "steam" (and then condense into visible droplets of water) is usually a waste of energy.

While there may be recipe directions which recommend vigorous "boiling", I would question as to why this would be necessary.

Surely to boil means to boil, ie let the water reach 100 degrees C. Other than by adding salt, surely the water can only reach a maximum of 100 degrees.

Sorry, I am not being combative, I think that I might be missing the point that you are making. Are you saying that the excessive heat agitates the water more? Surely any excessive heat just gets wasted rather than increasing the degree of bubbling? TBH, it is not something that I have really thought about. I am aware that you can "superheat" water above 100 in a microwave, but I am not aware of it being possible in a pan.

 

[EFLImpudence]

 

[opps]

View attachment 267997

A quick search suggests that simmering occurs at 85 to 95 degrees (for water).

When it comes to boiling, would the extended cooking times be linear or exponential?

On reflection, I guess that when it comes to breaking down carbs during cooking, you can get away with much lower temperatures. Perhaps we need a liquid other than water that has no taste and much lower boiling points.

 

[Harry Bloomfield]

While there may be recipe directions which recommend vigorous "boiling", I would question as to why this would be necessary.

Any cooking which requires the reduction in volume, such as jam making to thicken it by to boiling off the liquid, but that is one of the exceptions.

 

[Harry Bloomfield]

When it comes to boiling, would the extended cooking times be linear or exponential?

I'm having to do all of the cooking at the moment, but I notice no real difference in cooking time between simmering, usually with a lid and boiling. Boiling spuds for instance with no lid, the water quite quickly evaporates and will often need topping up. All that evaporated water will end up condensing on cooler walls. Simmering with a lid, takes much the same time, uses much less energy and very little of the water evaporates. I tend to put them on with no lid, burner on full until close to boiling, pop the lid on, then turn the burner to minimum. Often I will need to move the pan onto the very edge of the ring, even on minimum, because it is still too hot.

 

[FrodoOne]

I am aware that you can "superheat" water above 100 in a microwave, but I am not aware of it being possible in a pan.

I strongly doubt that one can "superheat" water (at "normal" atmospheric pressure) in a "microwave" - since it will boil (convert to vapour), when any attempt is made to raise it above 100 °C, no matter how much heat is applied.

Raising the "boiling point" of water is the purpose of a "pressure cooker".
Increasing the (atmospheric) pressure within a "pressure cooker" allows the boiling point of water to increase.

Conversely, on a high mountain (or at any height above "sea level"), water "boils" (converts to vapour) at a lower temperature.
(Trying to make a cup of tea on Mount Everest could prove to be "unsatisfactory" !)

Any cooking which requires the reduction in volume, such as jam making to thicken it by to boiling off the liquid, but that is one of the exceptions.

Reduction of the volume of water in a liquid is "forced evaporation".
This can be done in several ways including "Sun-Drying" and "boiling".
In all cases it is necessary to increase the agitation of the water molecules so that they convert from liquid to vapor.
This "conversion" takes quite a large amount of "energy".

As most will know, from their High School physics, the Latent Heat of Vaporisation of water is 540 times that which is required to raise temperature of the same volume of water by 1 °C.

This is one of the most important "physical factors" which makes "Life on Earth" (the "water planet") possible.

 

[JohnD]

I strongly doubt that one can "superheat" water (at "normal" atmospheric pressure) in a "microwave"

actually, you can. It tends to boil explosively if you then stir it.

 

[Harry Bloomfield]

actually, you can. It tends to boil explosively if you then stir it.

Yep, I have heard of it happening, though I have never seen it. You heat a cup of water in the microwave, take it out and it suddenly boils up violently. I have never studied the actual process.

 

[FrodoOne]

actually, you can. It tends to boil explosively if you then stir it.

Please post a reference to any experiment/demonstration showing that.

The suggestion which you are making is that water can be raised to a temperature above its "boiling point" (of 100 °C in "normal circumstances"), remain quiescent until "stirred" so that it "boils" - causing some of the "heat" of the over 100 °C water to change liquid water into water vapour.

Yep, I have heard of it happening, though I have never seen it. You heat a cup of water in the microwave, take it out and it suddenly boils up violently. I have never studied the actual process.

While you may "have heard of it happening" many people also have heard of "spontaneous human combustion".
Of course, this does not happen and there have been many programs/demonstrations showing how this was thought to have occurred (mainly in "Victorian" times) and the explanation.

The explanation is simply
the death of the victim (by asphyxiation, or other means) and
the subsequent ignition of the body fat (by a candle, cigarette, fire spark or other means)
within a closed room, becoming deficient in oxygen.

The result is a well chard body and a great deal of carbon/smoke within a relatively sealed and, otherwise, largely undamaged room.

(See https://en.wikipedia.org/wiki/Spontaneous_human_combustion )

 

[RandomGrinch]

 

[SUNRAY]

I imagine it's something similar with milk, if boiled until it starts rising then remove from microwave, let it settle then drop in a few grains of sugar.