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Author Topic: Does water boil faster with a lid on the pot?  (Read 20578 times)

Offline cheryl j

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Does water boil faster with a lid on the pot?
« on: 25/11/2011 05:29:54 »
My brother in law said it makes no difference. I thought putting the lid on slightly increases the pressure (Boyles law or something) and made water boil faster. Also, does putting salt in the water make water boil faster or does it keep noodles from sticking together.(My mother always did it, so I do it.) Or did she just like salty noodles?


 

Offline Don_1

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Does water boil faster with a lid on the pot?
« Reply #1 on: 25/11/2011 10:44:59 »
Are you having a bad food day Cheryl? Noodles can be pretty tasteless and boring, a bit of salt helps.

Put the lid on the pan and yes it will boil faster. Never mind Boyle's Law, the simple fact that you are containing the heat in the pan rather than allowing heat to escape will shorten the time for the water to boil. Also, it reduces the amount of energy required to keep it boiling.
 

Offline CliffordK

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Does water boil faster with a lid on the pot?
« Reply #2 on: 25/11/2011 11:05:35 »
The lid on the pot should actually increase the pressure inside...  slightly...  and thus would raise the boiling point...  slightly...   more if it is a pressure cooker.  Thus, you would think it would actually increase the time until boiling.

However...
I agree with Don.  It will contain the heat.  And, thus decrease the time to the BP.

I assume the problem is somewhat the same idea that sweating will help cool down your body (and wearing a slicker on a hot day will make you very HOT).

At temperatures below the BP, your pot still releases a lot of steam due to a lower vapor pressure (humidity) in the air, and a higher vapor pressure in the water, although until it reaches the BP, it is still less than 1 ATM.

Anyway, so releasing the steam takes a lot of energy, and cools the pot.

Putting the lid on the pot increases the partial pressure of the water vapor in the air, and thus prevents the water from evaporating or steaming.  Thus, it traps the heat, and your pot heats up quicker.

One might also expect, that if you took an uncovered pot into the bathroom while taking a shower, it would also increase the atmospheric water vapor pressure, and thus also cause less water to evaporate, and the pot to heat up faster than it would at a lower humidity.

Sorry...  I'm not considered an Italian Chef.  The temperatures of a strong rolling boil, and a weak boil are about the same, and you'd have more variability with altitude than by playing around with the temps.  I assume a strong rolling boil will provide some mixing of the spaghetti, something you could also accomplish with a fork.  If you bring the water up to just barely boiling, you wouldn't get the added mixing provided by the steam cavitation, and might get more clumping of your pasta.
 

Offline Geezer

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Does water boil faster with a lid on the pot?
« Reply #3 on: 25/11/2011 18:26:14 »
The fastest way to get it to boil would be to seal the lid on the pot and hook it up to a vacuum pump :D
 

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Does water boil faster with a lid on the pot?
« Reply #3 on: 25/11/2011 18:26:14 »

 

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