Infusion

Infusion is a method of extracting soluble compounds from a solid material by steeping it in a liquid. The process is widely used in cooking, beverage preparation, and medicine. Traditionally the material is plant matter such as leaves, flowers, or spices, and the liquid is water. It differs from decoction, in which the material is boiled to break down tougher tissues.

In culinary contexts, infusions produce beverages and flavorings. Tea is the prototypical example, made by infusing tea leaves in hot water. Herbal infusions can use a variety of plant parts, with temperatures and steeping times chosen to optimize flavor while avoiding bitterness. Infusions can be hot or cold; hot infusions extract flavors quickly, while cold infusions yield milder flavors over longer periods. Beyond drinks, infusions flavor syrups, oils, and spirits by allowing the plant material to impart aroma and taste.

Alcoholic and botanical infusions are also common, where ingredients are steeped in spirits such as vodka, rum, or wine to extract flavors for liqueurs, bitters, or flavoring agents. The resulting product may be strained or filtered before use.

In medicine, infusion refers to administering fluids, nutrients, or medications intravenously. An IV infusion delivers solutions through a venous catheter at a controlled rate, often using gravity drip systems or infusion pumps. This approach provides hydration, electrolyte balance, and sustained drug delivery under medical supervision.

Quality and safety considerations include the starting material’s freshness and cleanliness, water quality, appropriate temperature, and appropriate duration. Some substances can degrade or become unsafe when overheated or left to infuse too long.