Right now I'm cooking. In a reasonable size stock pot is a big jumble of stock, chicken, wine vegetables and a few herbs. It'll probably be very nice in a couple of hours when the sauce has reduced and the vegetables are nice and soft.
Now, in order to keep this pot simmering away gently I need number 2 on the rather irritatingly non-linear scale controlling the gas. BUT, if I turn it down do 1.887 ish, the simmering stops. Because the equilibrium between energy gain from the gas and energy loss from the pot is reached at a temperature below that required for a satisfactory simmering sound.
"just leave it at 2" you may scream, in anguish. But "NO" I cry, there was probably someone in a cave telling Ug not to bang the rocks together, and even the Luddites agree that guy was a Luddite. So, I put a lovely folded fluffy tea towl on top. NOW simmering could be sustained at 1.887 gas... EUREKA! A gas saving!
So, to capitalize upon this, a series of flame retardant circles the size of all the pot/pan lids should be supplied with pots/pans at purchase. Then everyone can get a little confused and lose them.-- bs0u0155, Jan 08 2014 A cosy for use while cooking may be original enough however dubious.-- rcarty, Jan 08 2014 " I tell you Mabel her pot lid cosies were filthy. I don't think she ever washes the darn things. Useful as they are some people should not be allowed to own them. Did you hear about... "
(cosy s?)-- popbottle, Jan 08 2014 Alternatively, a double-walled lid may provide similar function with fewer components.
I do, however, demand more sophisticated steam handling be incorporated. It's a failing of every lid I've encountered. I recommend a small tube&ball system to more accurately estimate steam efflux rate.-- bs0u0155, Jan 08 2014 random, halfbakery