Inner Alchemy (Neidan): Refining Jing into Qi (煉精化氣)

Liàn Jīng Huà Qì (煉精化氣) is the first transmutation of Neidan: refining reproductive essence (jing) into vital breath (qi) within the lower dantian (elixir field). The practitioner uses regulated breathing, visualization, and stillness to seal the 'leaking gates' and redirect jing upward through the Microcosmic Orbit (xiǎo zhōu tiān). The Cantong Qi — the oldest systematic Neidan text — describes this stage through the metaphor of fire beneath the cauldron (dǐng), where raw material is slowly cooked into a subtler substance. This first refinement is the most physically demanding of the four Neidan stages, and failure here is the most common reason practitioners never advance.