redistilled

Redistilled describes a liquid that has undergone a second distillation after the initial separation of components. The purpose is typically to increase purity, remove impurities, or to adjust the relative concentrations of volatile components. Redistillation can be performed on a wide range of materials, including water, solvents, essential oils, and alcoholic spirits.

Process: The redistillation is carried out in a distillation apparatus where the distillate from the first pass is heated again. Depending on the material, a fractional distillation setup, such as a column, may be used to improve separation. Operators select reflux ratios, temperatures, and collection fractions to separate desired constituents from unwanted ones, or to achieve a target proof. In some cases, redistillation may involve changing the composition of the starting material, for example by adding water or another solvent to tailor boiling behavior.

Applications: In chemistry and pharmaceutical manufacturing, redistillation helps achieve higher purity and remove trace impurities. In essential oil production, it can refine fragrance profiles. In water treatment, redistilled water is produced to remove dissolved species beyond a single distillation. In alcoholic beverage production, redistillation (often termed rectification) can produce neutral spirits or adjust flavor by separating congeners.

Safety and regulation: Distillation involves flammable liquids and vapors; improper operation can cause fires or pressure hazards. Many jurisdictions regulate home distillation of alcohol, and professional redistillation is performed under controlled conditions with appropriate permits and equipment.

See also distillation, rectification, azeotrope.