Here I am putting on my kitchen detective forensic hat :-) What determines water evaporation rate for a cookware? Assuming identical food is being cooked, and there is a cover: 1. The BTU output of the stove fire. 2. The thermal conductivity of the bottom of the cookware. 3. The thermal conductivity of the side wall of the cookware. 4. The thermal conductivity of the cover. 5. The size of the cookware. 6. The temperature of the room when the food is being cooked. 7. The leakage of the cover. ---------------------------------------------------------- 1. There is no way to make sure that you are getting the same BTUs with gas or electric stoves. The controls for both are highly inaccurate. The only way to compare is to use an induction cook top. You can get the same BTUs from the induction cook top using the dial or push button control. For low temperature cooking, a small amount of BTU difference renders the cookware comparison meaningless. 2 & 3. How thick, what kind of cast iron and enamel, and the shape will make a big difference on how many BTUs the cookware can capture from the stove heat. 4. Likewise, the cover determines the rate of BTUs escaping and ability to condense water vapor back to water into food again and again. 5. The larger the size, the more BTU escaping by conduction and radiation to outside. 6. Of course, the room temperature should be the same for the comparison. 7. The leakage - I believe the leakage of the cover has very little effect, almost zero, to the evaporation rate of the food being cooked. If the total BTUs supplied by the stove are less than the BTUs lost by the cookware, the food will be simmering without ever reaching 212 F boiling. There will be no steam pressure building up. In this case, any small leak by the cover will have no effect because there is no pressure to push water vapor out. If not, the BTU build up will cause the food to boil, and steam will cause the pressure to build up inside the vessel. How will a little leak affect the rate of evaporation? A10 inch cast iron cover is about 78 sq. in. and weighs about 3 to 4 lbs. Atmospheric pressure is at 14 lbs/ sq. in. Over a 10 inch cover that comes to 1099 lbs. A pressure cooker to effectively change the boiling point works at 15 lbs / sq. in. and that comes to 1177 lbs. So how much pressures/temperature change can happen by a cover weighing only 3 to 4 lb against 1099 lbs? I say not much at all. It is interesting for some recipes the time and food wasted in forming dough around a cover to prevent steam from escaping. I believe a well designed cookware cover should allow a small amount of steam to escape. A perfectly fitting cover will cause the cover to rhythmically open and close, making non-stop banging noise during the whole cooking time. dcarch

I've never had any rust on the rims of my Le Creuset french ovens. I use the bouillbaisse pots the most. In her book "All About Braising" Molly Stevens suggests putting a piece of overlapping parchment paper under the lid and pushed down close to the contents in the pot. I find that tip very useful in keeping the food moist and tender when braising for long periods in the oven. seagrass

I haven't tried any alternatives for LC but do swap lids on other vessels. My all clad lid with glass fits on my CIA for example. Give it a try

Amazing! Is this just from your memory that F is for 26 cm or were you able to find a website? I feel like I scoured the internet to no avail. Thank you for your help :)