A steamer for sandwich buns, bagels, croissants, cakes, vegetables, pastas, and other foods delivers fixed amounts of water onto a hot, dry platen through a vertically-oriented water conduit which is also thermally insulated from the hot platen and made from thermally insulating materials. The vertically-oriented water conduit retains water after a water supply is shut off at the beginning or end of a steam generating cycle. Orienting the conduit vertically reduces the surface area of liquid water exposed to air. Insulating the water conduit from the hot platen reduces the rate at which water standing in the conduit evaporates. Tubes used in the water conduit are insulating and easily removed from the water conduit assembly and flexible. Minerals that precipitate out of solution and become deposited onto the flexible tube are easily removed by flexing the flexible tube.