[header] How to use a double boiler [title] Gather your materials. [step] You will need both the bottom pot and the upper pot; you will not need the lid that came with your double boiler, unless the recipe or project specifically calls for one. If you do not have a double boiler, you can make your own using a large pot and a shallow, heat-resistant bowl that can fit over it. 
[substeps] The bowl in your homemade double boiler should fit snugly onto the large pot. There should be no gaps or spaces between the bowl and the rim of the pot.