louching

Louching is a phenomenon observed in certain alcoholic beverages, most notably anise-flavored spirits like absinthe, ouzo, and pastis, when they are mixed with water. This process involves the spontaneous emulsification of essential oils, primarily anethole, which are responsible for the characteristic licorice-like aroma and flavor. When water is added to the spirit, the alcohol concentration decreases, causing the hydrophobic anethole to become insoluble in the now more aqueous solution. This leads to the formation of tiny droplets of oil that are dispersed throughout the liquid, resulting in a cloudy, milky, or opalescent appearance. The degree of louching can vary depending on the specific spirit, the ratio of water to spirit, and the temperature of the mixture. Some spirits are specifically formulated to louche readily, as this visual transformation is often considered an integral part of the drinking experience for these beverages. The term "louching" itself derives from the French word "loucher," meaning to squint or to become cloudy.