As many of us have found, we can cut some weight out of our gear by tossing a heavy metal lid and using something pretty skimpy. To understand this better, we might ask the question: Exactly what does a cook pot lid do?
If you are just boiling water, heat and steam is given off from the water surface, and if you can contain that somewhat, you will get a quicker boil time and waste less heat and fuel. You probably do not want to have a completely tight lid, because then the steam would be under pressure and could blow the lid off in your face. That's one reason why lots of lids have at least one little pressure relief hole. That way, you retain 99% of your heat but it never gets unsafe. Some use a pasta pot with a lid with multiple holes in it, and that is so you can drain out the pasta water easier.
If you have a tasty stew simmering in the pot, then keeping the lid on is probably a good thing. It emits less odor for the wildlife to find. It keeps the juices condensing and running back into the simmering pot, so that keeps the stew from drying out so quickly.
Some of us use titanium for our cook pots, but aluminum for the lids. The lid never seems to get subjected to flame temperatures, so anything will last as long as you don't stomp on it. Personally, I do not like the aluminum of a turkey roaster pan because it tends to have sharp edges on it. Multi-layer aluminum foil seems to work OK for me, and the edges are soft. Some are using plastic or carbon fiber lids.
One guy had a lid that was crude but effective. He had a circle of ordinary corrugated cardboard covered with aluminum foil.
Some lids have handles. Mine doesn't. Some like wooden handles, plastic handles, or any solid wire handle that will fold. String loop handles are even lighter, but you have to put a twist in the loop so that it doesn't just sit on the lid surface.
–B.G.–
