Herbal Preparations: Infusion or Decoction?
While they may not realize, most people infuse an herb (an infusion) without thinking about it and call it herb tea. They put a tea ball or a tea bag in a cup of boiling hot water and steep (steep – to soak in water to extract a component of a plant) for 5 minutes or so and drink it. Infusions are used to extract vitamins and volatile ingredients from quickly perishable, fresh or dry herbal pieces (leaves, flowers, small non-woody green stems, orange zest, for example). Popular infusions are from plants that are so, SO good for you in general like peppermint or chamomile. You put the fresh or dried herb in a cup, pour on the boiling water and BOOM, Infusion! The keyword here is “short time in boiling water“. The small amount of time the herb is in a super hot environment helps it retain volatile (as in fleeting) ingredients that can perish quickly through vapor or heat.
A decoction, on the other hand is used to extract “harder to get” ingredients from a plant including bitter principles like tannins, alkaloids, saponins, etc; from hard or more woody plant material like bark, roots, and seeds. These more hardy materials generally require boiling in water for at least 10 minutes and often are allowed to steep for additional hours. Sometimes a decoction is “boiled down” (boiled until the water is maybe halfway reduced) which makes the decoction concentrated so that (possibly) water needs to be added before drinking or, it can be added, after decocting, to a tea.
Note: Think dandelion root and dandelion leaf together. If you boiled the leaves in water with the root, you would lose some of the more easily lost vitamins from the tender leaf. But the root needs to be boiled in order to extract the minerals. The definition of the word decoct means – to extract (the essence or active principle) from (a medicinal herb or similar substance) by boiling.