An infusion is used when trying to maintain the volatile oils of delicate plant parts like flowers and soft leaves in the preparation process. The herbs or plants are not boiled, but instead steeped.
The best method is to pour water that has just been brought to a rolling boil over the recommended herbs. Cover for ten to twenty minutes in a non-plastic container (glass is preferred).
Another method is to make a sun-tea by placing herbs in water under direct sun exposure for a few hours.
Strain, drink as directed.