there is no cooking process before sealing, the raw fish cooks in the can, the hand cranker seals the tin by folding metal over on to the lid just like cans of food at home,pressure cook at 12to 15 pounds for 90 minutes after lid is cranked onto canafter cookingput into cold waterand your done,cans can be upside down or sidewise in cooker,so usually you can fit a lot into your pressure cooker.