KanjiJLPT N2
Steam

steam, heat, sultry, foment, get musty

Mnemonic

You lay fresh grass over a bamboo steamer filled with water, balanced on one iron grate above crackling flames. Instantly, billowing steam surges upward through the grass, wilting it soft — a perfect steamed dish rising from fire, water, and heat working together.
Additional thoughts
Visualize the kanji as a vertical stack: grass on top, water and one in the middle, flames at the bottom — exactly how a real steamer works, heat rising from bottom to top.
Quick recall
Grass over water on one rack above flames produces steam.

Details

The keyword for 蒸 is steam. This kanji refers to the process of steaming, where water is heated to produce vapor that rises and envelops whatever is above it. It encompasses both the physical phenomenon of water turning into steam and the cooking method of steaming food. By extension, it can also convey a sense of something being sultry, muggy, or suffocatingly hot, as in humid weather where moisture hangs heavily in the air.
On'yomi
じょう、せい
Kun'yomi
む.す、む.れる、む.らす