Does stirring water help bring it to boil faster?

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Discussion Overview

The discussion centers on whether stirring water in a large pot affects the time it takes to reach boiling point. Participants explore the implications of convection, heat transfer, and experimental approaches to this question.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested, Experimental/applied

Main Points Raised

  • One participant suggests that stirring increases convection, which could enhance heat transfer by keeping cooler water in contact with the heat source.
  • Another participant proposes that natural convection might already be sufficient for mixing, implying that stirring may not significantly impact boiling time.
  • A different viewpoint mentions that stirring could contribute additional heat from the mechanical action, albeit a small amount, potentially reducing boiling time.
  • Concerns are raised about the possibility that stirring might lead to heat loss due to increased surface waves and the need to remove the pot cover to stir.
  • One participant recommends conducting an experiment to measure the effects of stirring versus leaving the pot alone.

Areas of Agreement / Disagreement

Participants express differing views on the effectiveness of stirring in reducing boiling time, with no consensus reached on whether it is beneficial or detrimental.

Contextual Notes

Assumptions about the efficiency of natural versus forced convection are not fully explored, and the potential impact of heat loss due to stirring remains unresolved.

Who May Find This Useful

This discussion may be of interest to those exploring heat transfer principles, experimental physics, or practical cooking techniques.

AHVincent
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Is it faster to leave the pot alone until it boils or to stir it every few minutes to increase convection?

This is for a very large pot of over 50 litres using a 50 000 BTU commercial gaz burner at full power.
 
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You would expect faster heat transfer from flame to water when the temperature difference is high. So stirring the water (forced convection) will keep water with lower temperature in contact with the walls of the pan and should ensure more heat goes into the water and less is wasted into the surrounding air.
 
My guess is that natural convection will mix it reasonably well in the first place, so there won't be much of a difference. You could always try it as an experiment (all you need is a stopwatch), and let us know the results...
 
And weren't Joule's experiments done by stirring a fluid? Ideally the heat generated by stirring the pot would be added to the heat from the element, I know it would be very small, but that would also shorten the time to boiling.
 
The stirring element might take some of the heat from the water. Waves caused by the stirring might also increase heat loss...and ultimately, you probably have to take the cover off to stir it.

I say just let it be.
 
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