蒸制将药材置蒸具中，以水蒸气加热。清蒸不加辅料；酒蒸、醋蒸等则先拌辅料再蒸。蒸后可改变质地、降低毒性或调整药性。何首乌、熟地黄等经典品种多经蒸制。
Steaming heats material with steam. Clear steaming uses no auxiliary; wine or vinegar may be mixed in first. Steaming can alter texture, reduce toxicity or modify properties. Classic examples include processed Polygonum multiflorum and Rehmannia.
「九蒸九晒」是反复蒸后晒干的传统工序，常见于何首乌、熟地等。传统认为多次蒸晒可缓和药性、增强补益之效。实际操作中「九」多为约数，强调反复处理；现代生产中有严格的工艺参数与质量控制要求。
“Nine times steamed and nine times sun-dried” is a repeated process traditionally applied to materials such as He Shou Wu and Shu Di Huang. Tradition holds that repetition moderates potency and enhances tonifying effects. In practice “nine” is often approximate; modern production uses defined parameters and quality controls.