decocting

Decoction, or decocting, is a method of extracting soluble components from plant materials by simmering them in water. It is distinct from infusion, which relies on steeping in hot water without prolonged heating. Decoction is commonly used in traditional herbal medicine, in the preparation of certain culinary stocks, and in the production of pharmaceutical extracts.

Materials used for decoction are typically tough plant parts such as roots, bark, seeds, or dried fruits. The plant material is cleaned, cut or broken to increase surface area, and placed in water. A common starting approach is to use enough water to cover the material, with additional water added as needed to maintain the level during cooking.

The procedure involves bringing the mixture to a boil and then simmering gently for a period that varies with the material. Many herbs and seeds are decocted for about 20 to 60 minutes, while harder materials such as roots or bark may require 1 to 2 hours. Foam is skimmed off as it forms. After cooking, the liquid is strained while hot and the solids are discarded. The decoction can be used immediately or reduced to a concentrate. In some traditions, a second extraction with fresh water is performed on the same solids.

Uses and considerations include the extraction of water-soluble constituents such as flavors, tannins, sugars, and various phytochemicals, yielding a strong, sometimes astringent liquid. Decoctions tend to be more robust than infusions and may be harsher on sensitive ingredients. They should be cooled and stored promptly; refrigeration is common, with typical use within a few days, or the liquid may be concentrated or frozen for longer storage.