526493 Fri Jun 06 13:03:25 -0700 2008 16 27 General Chowhounding Topics 0 3756879 Does anyone know if water boils faster with the lid on or without the lid? I have asked a number of people.....I want to know what most of you think. crn Fri Jun 06 13:03:26 -0700 2008 67197 crn 1 3756924 Heat rises. Since a lid will slow this action some, a pot with lid will boil slightly sooner, although is shouldn't be a large effect on a standard sized pot on a standard range top. The larger the volume of water and the smaller the burner, more effect since the time to boil and time to transfer heat to the room would be longer. Fri Jun 06 13:14:11 -0700 2008 3756879 65193 EdwardAdams 2 3757034 It traps the rising heat and definately boils faster. Fri Jun 06 13:42:33 -0700 2008 3756924 24648 Sean 1 3757148 As others have noted, it boils faster with the lid, since the lid traps the heat. Fri Jun 06 14:19:52 -0700 2008 3756879 11028 DanaB 1 3757309 With lid - for reason stated. BTW, those folk who told you "without"......did they suggest a reason why? Fri Jun 06 15:07:08 -0700 2008 3756879 154102 Harters 2 3759292 Here's a guess. Because if it's a heavy lid the pressure inside the pot will rise slightly causing the boiling point of the water to increase. Note that the water may reach 100°C (at sea level) faster but it won't *boil*. Now when you lift the lid off you have released that pressure and the water may boil furiously (like super heating water in the microwave) causing a burn. Me personally, always with the lid on but I'm careful when removing it. I also don't salt my water until it is at a rolling boil. Not anything to do with how fast it will boil; I don't like a big pile of undissolved salt sitting on the bottom of my pot and possibly reacting with the metal. Sat Jun 07 15:15:34 -0700 2008 3757309 161386 kmcarr 1 3757778 Boiling a pot of water with the lid on is 1/3rd faster than without the lid on. Fri Jun 06 18:19:19 -0700 2008 3756879 148845 scoopG 1 3765067 There are several things that come into play. First of all, the lid traps the higher 'humidity' which reduces evaporative cooling. It tends to contain and reflect heat. Lastly there is a micro increase of pressure that also helps reduce evaporative cooling. There is some interesting physics involved with boiling liquids. Mon Jun 09 17:43:37 -0700 2008 3756879 169832 NVJims 1 3775914 without a doubt, with a lid. WON http://whatsonmyplate.wordpress.com Thu Jun 12 18:18:29 -0700 2008 3756879 92591 wontonfm 1 3775957 Mother always said, " a watched pot never boils." Thu Jun 12 18:33:43 -0700 2008 3756879 75332 Gio 2 3776012 sorry gio but jfood's mom told him the same thing and he disproved this theory when he was an obnoxious teen in front of his mom. needless to say he went to bed without dinner that night. Thu Jun 12 18:49:12 -0700 2008 3775957 11290 jfood 3 3776133 Oh dear sorry for that loss jfood! I was also told to not put the lid on the macaroni water after the pasta was thrown into the water. Later in life I learned that lid on - lid off made no difference to the cooking time. Good thing The Mater wasn't looking..... Thu Jun 12 19:29:50 -0700 2008 3776012 75332 Gio 2 3776858 You know, I've done some thinking about this old maxim, and I've concluded that our modern interpretation is wrong. In the old days (and today), when you boiled porridge or something similar in a pot, the one thing you didn't want was for the pot to boil over, possibly putting out the fire - so you paid close attention to the pot in order to prevent that from happening (by stirring, moving the pot off the flame briefly - or lowering the burner, today). Hence the helpful hint: a watched pot never boils <over>. This makes sense to me in a way that the other interpretation never did - after all, as jfood has noted, it's very easy to prove the statement in that sense is simply false. YMMV, of course. :) Fri Jun 13 05:30:45 -0700 2008 3775957 12622 Striver 3 3776986 "Hence the helpful hint: a watched pot never boils <over>." Well now, that makes perfect sense to me as well!! Fri Jun 13 06:25:58 -0700 2008 3776858 75332 Gio 3 3777114 Huh. I always thought that expression was about patience. Who knew! ~TDQ Fri Jun 13 07:09:15 -0700 2008 3776858 12005 The Dairy Queen 3 3777460 jfood loves that interpretation, very refreshing. now he just needs to take that swinging up-down motion of the pointing index finger and the shrilly statement out of his head and replace with this positive spin on the addage. thanks for making jfood's day. Fri Jun 13 08:48:24 -0700 2008 3776858 11290 jfood 4 3777471 No prob...incidentally, after posting the above I did some quick net checking and found that my interpretation had been suggested by others (no surprise), but that there's nothing that really supports it. It makes sense to me, though, so I'm sticking with it! Fri Jun 13 08:52:23 -0700 2008 3777460 12622 Striver 1 3776084 With lid, assuming you're boiling cold water. You have to get the water up to temperature first, so evaporative cooling and vapour pressure aren't an issue (at least initially), keeping the heated vapour in, and transferring heat to the liquid water are a bigger factor. If you're boiling hot water, and just trying to get bubbles, it might be faster to leave the lid off. Thu Jun 12 19:12:35 -0700 2008 3756879 69044 hsk