Choosing a pot for a long-cooked broth
The first time a pot is too small, you notice it when you try to stir. For a long simmer I look for room above the waterline and a cooking surface suited to what will spend hours against it.
Match the material to the food
A tomato-rich soup and a plain broth put different demands on cookware. BfR advises against contact between uncoated aluminium and acidic or salty food. Check the actual cooking surface: an aluminium core enclosed inside a pan is different from bare aluminium touching the broth.
For your own kitchen, follow the manufacturer's instructions for long cooking and the foods you plan to use. Inspect the lining or coating before putting a pot on for several hours, and replace cookware with damaged food-contact surfaces when the manufacturer advises it.
Leave room to work
Choose the pot after you’ve thought about the bones as well as the water. Put in the solids first, then see how much room is left to stir and skim without filling it to the rim. A five-litre pot is not a recipe for five litres of soup. For a pressure cooker, check the manufacturer’s fill limits and release instructions before you start.
Updated · Alexander Pichugin