Inquiry 2: best materials for cooking pots

Good cooking pots should (i) conduct heat well from the burner to the food, (ii) heat evenly, (iii) not react with the food, (iv) be strong and durable, and (v) have handles that stay cool.

• Best conductors: copper (k ≈ 400 W/m·K), aluminium (≈ 237), then iron (≈ 80); stainless steel is a poor conductor (≈ 16) but is hard, rust-free and non-reactive, so good pots are often stainless steel with a copper or aluminium core in the base.
• Other factors: price, weight, resistance to corrosion, safety of the metal for food (aluminium reacts with acidic food; copper needs a lining), non-stick coatings, and insulating handles of wood or plastic (poor conductors). Energy is saved when the pot's base is flat and thick, matches the burner and has a lid.