A decoction is a sort of liquid soup, strained from the boiled parts of a healing plant. Several parts of a plant can be used (twigs, roots, berries and leaves and flowers) and up to several plants in a decoction depending on the remedy recipe.

The ingredient ratio of herb to liquid is usually 1oz to 1pt or 25-30g to 500-600ml. Boil parts then simmer for twenty minutes (avoid aluminum pots/saucepans), strain and allow to cool; only the strained liquid is used. Decoctions can be sweetened with a little brown sugar, molasses or honey. Some decoctions are mixed with larger quantities of honey or a molasses to make Syrup.

Decoctions and syrups can be refrigerated. Most decoctions will keep for three days.