Steam Releases a Lot of Heat When It Condenses into Water

Conversely, when water vapor hits a cool surface and condenses into liquid water, it gives up that same high heat of vaporization. This is why steam is such an effective and quick way of cooking foods compared with plain air— also a gas—at the same temperature. We can put a hand into an oven at 212°F/ 100°C and hold it there for some time before it gets uncomfortably warm; but a steaming pot will scald us in a second or two. In bread baking, an initial blast of steam increases the dough’s expansion, or oven spring, and produces a lighter loaf.