Laugung

Laugung is a term used in German to describe a process of washing, rinsing, or extracting soluble substances from a solid material with a liquid, typically water or a solvent. The meaning varies by field, but the common idea is the transfer of soluble components from the solid into the liquid.

In brewing, Laugung is closely associated with Läutern, the step in which mashed grains are washed with hot water to extract fermentable sugars and separate the wort from spent grains. The mash is transferred to a lauter tun to form a porous bed; a recirculation or vorlauf clarifies the wort, and sparging with hot water (around 76–78°C) rinses remaining sugars from the grain bed. The collected runnings form the wort, which is then boiled with hops. Laugung in this context aims to balance extraction efficiency with the avoidance of undesirable compounds, with temperature, water-to-grist ratio, and pH influencing extract yield and wort color and body.

In other contexts, Laugung describes leaching or washing processes used to dissolve and transfer desired constituents from solids into a liquid. This includes chemical or hydrometallurgical leaching of ores using acids or alkalis, purification steps in sugar or starch processing, and cleaning or retting of fibers. The principle is the selective dissolution of targeted components, followed by separation and recovery of the solute.

Etymology and usage: the term derives from the German Lauge, meaning wash liquid or solution. In specialized fields, Laugung serves as a general descriptor for washing or leaching operations, while specific terms like Läutern or Leaching may be used for particular applications.