Cold infusion

The coarsely powdered herbs are kept in water overnight and rubbed with hands in morning and strained. The liquid obtained is called Hima kalpana or cold infusion in ayurveda. The fragrant and shita virya dravya on heating converts into Ushana virya and the fragrant and volatile oils are faded away and thus, such substances should not be heated and in order to receive their essential part (saara bhaaga) hima Kalpana is prepared.