Decoctions are prepared similarly to infusions, except that they are specifically for hard & woody parts of plant such as roots, rhizomes, wood, bark, nuts & seeds. These parts have tougher cell walls that require a stronger extraction to ensure that the active constituents are transferred into the water. More heat is needed than for infusions, and the herb has to be boiled for a longer period of time.
How to make a Decoction:
Herbs to use in a decoction: