Decoctions are used for hard bits of the plant, such as roots, twigs, branches & barks.
-> A decoction is a fancy word for bringing the water (to which you've added the herbs) to a boil, then lowering it to a simmer, covered, and letting it cook for 20-30 minutes. Some roots can be really tough and can be left to simmer for 45 minutes to 1 hour. The usual way to gage the time is once the water has boiled down to half (through the process of slow evaporation), it is ready to be drunk. Simply strain out the herbs using a fine mesh sieve (you can even add a coffee filter to the sieve first if you like). The herbs can be composted and your beautiful tea can be drunk right away (let it cool a bit first!) and the rest refrigerated for 2-3 days.
The standard ratio of herb to water is 1 ounce herb to 4 cups water. A decoction then means this amount has been reduced to half (there is 2 cups of tea in the pot for you to drink).
NB. Since herbs are sensitive to metal, you want to ideally use a glass or ceramic pot. 2nd rate is to use a stainless steel pot (which really translates as = invest in a glass or ceramic pot!).
-> A double decoction means that the amount of water left in the pot has been reduced to 1/4th its amount. That means the 4 cups of water has cooked down to 1 cup (there's 1 cup left in the pot). Sometimes people also make double decoctions in this way: once the water has cooked down to 2 cups (or by half), they add 2 cups of water again (the amount that was lost), and boil it down again to half (2 cups are left in the pot to drink). Either way, making the herbs boil for a longer means that the tea, or medicine, is much more potent than a decoction. Once again, strain out the herb, cool and drink. Refrigerate the remainders for several days in the fridge.
Standard amount to be drunk: 2-4 cups daily.
NB. Bitter herbs may still taste bad, even when boiled this way. Often, licorice root is added to Chinese herbal formulas to mask the task, while in Western herbalism honey is often used. Stevia or other low calorie sweeteners (monk fruit, erythritol, xylitol, etc.) can similarly be used to add a sweet element. Non-dairy milks can also be added.
Interesting tidbit: in terms of medicinal potency equivalency:
-> 1 cup infusion (flower & leaf) = 1/4th cup decoction = 1 TBsp double decoction
Who loves free Herbal Recipes?
I do! I do!