Many people are familiar with using thermos bottles for hot beverages, like coffee or cocoa, but many thermoses are designed specifically for hot food. Using a thermos increases your options for taking lunch with you. Foods, such as soup or baked beans, that would become unsafe to eat if left to sit all morning can stay piping hot if prepared properly and put into a thermos.
Hot lunch foods that are liquid or semiliquid work well in a thermos. Dry foods will not stay hot in a thermos. Soup makes for a good thermos lunch, as do stew and chili. Pastas, curries and casseroles that are prepared with a substantial sauce will also stay hot in a well-sealed thermos.
Before adding food, prepare the thermos by pouring boiling water into it and letting it sit for a couple of minutes before pouring the water out. Meanwhile, heat the food until it is hot to the touch. To ensure even heat distribution, heat the food in a pot on the stove rather than using a microwave. Food should be heated to at least 140 degrees Fahrenheit to be safely stored in a thermos. Once you pour the food into the bottle, twist the lid on tightly so the heat does not escape.
Always start with a clean thermos so your food won't be contaminated by bacteria. Heat the food just before you leave for work or school so the food does not have to sit in the thermos for longer than necessary. If the temperature of the food drops below 140 degrees Fahrenheit for a period of longer than two hours, it runs the risk of forming harmful bacteria and is no longer safe to eat. If you are sending the thermos to school with a young child, advise her to ask an adult to help open it so she does not scald herself with the contents.
At the end of the day, dispose of any leftover food from the thermos. It is not safe to eat thermos leftovers. Clean your thermos by rinsing it with boiling water, then washing it by hand with soap and hot water. Let the bottle dry completely before replacing the lid. Unless your thermos is labeled as being dishwasher-safe, do not place it in the dishwasher.