In a hot pan over a gas flame, the contents will cook or boil in the high heat. But only after you turn off the flame will the contents begin to visibly steam. Is the pan too hot for steam? Perhaps the steam is invisible?
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After you turn off the heat, the air in the vicinity of the pan cools down, while the food is still hot, which causes condensation (which is what steam is the product of).
While the heat is on, it isn’t just the pan and its contents that are hot but also the air in the vicinity, which means a lower temperature differential, insufficient for any significant amount of steam to form.
Steam is invisible, it is a gas. Technically, “steam” is water that is hotter than the boiling point. The waste product of burning natural gas on your stovetop is also steam.
It is when the steam is cooled that water vapor becomes visible, as the air can no longer hold water vapor molecules (humidity) without sufficient kinetic energy, and it begins to collect in clumps of liquid molecules that diffuse light. The same effect happens from simply cooling humid air and not steam: your dryer vent or your breath on a cold day.
Perhaps the heat radiated by the pan and convection currents of hot flame keeps the air above hot, and carries moisture away before you see it precipitate out..
“Steam” can mean two different related things:
* Dry steam, which is pure water vapor. Dry steam is invisible aside perhaps from the shimmering you see in any hot column of air.
* Wet steam, which is water vapor *and condensed droplets of liquid water suspended in the air*. Wet steam looks like a cloud.
When the food is very hot, the water vapor stays in gaseous form until it dissipates. That (dry) steam is invisible. Once the food has cooled slightly, the vapor cools enough to condense while it’s still concentrated, producing visible (wet) steam.
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