Steam is formed at 100°C but I see “steam” being produced at less than that temperature. What is that and why isn’t it steam?
In: 33
As another comment explains steam, or water vapor, isn’t visible. We tend to associate visible small droplets of water suspended in air with steam, even though it’s a different thing. That occurs because shifts in temperature affect how much water vapor air will hold, and a jet of actual water vapor (coming out of a kettle on the stove, for example) will appear cloud-like, because 100 C water vapor will mix with cooler air, condensing out tiny visible droplets, which will be reabsorbed in gas form again into surrounding air, instead of forming a tiny rain cloud over your stove.
A cloud is the same sort of thing, or fog is, droplets suspended in air because a shift in temperature changed how much moisture the air could hold. Then actual rain might occur, or in the case of fog some degree of dew is going to happen (connected with the concept of dew point, the temperature at which water vapor in air is going to change phase in that way).
Moving off this central topic, tea enthusiasts (which I am one of) sometimes age-transition some tea types (sheng pu’er, mostly), helping it ferment over time, by storing it in relatively humid controlled environments. If you get the shift in temperature input all wrong you might trigger condensation, which goes very badly for stored tea, because it will become damp, and mold quickly. It’s rare for this to happen because temperatures don’t usually shift quickly inside your house, especially in some closed closet or cabinet area, but once in awhile people will ask why moving a box of tea from one place to another caused this (condensation and mold), and temperature change is a likely reason.
Latest Answers