Britannica Sources used in this answer

How does a condenser change alcohol vapor back into liquid?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

distilled spirit The fermentation and distillation process for producing whiskey. The production of whiskey begins with grinding grain into a meal, which is cooked. Malt is introduced to the meal, which results in mash that is cooled and pumped into a fermenter, where yeast is added. The fermented mixture is heated in a still, where the heat vaporizes the alcohol. The alcohol vapours are caught, cooled, condensed, and drawn off as clean, new whiskey. This liquid is stored in a cistern room, and water is added to lower the proof (absolute alcohol content) before the whiskey is placed in new charred oak barrels for aging and later bottling.

In the context of producing a distilled spirit, a condenser functions by removing heat from the alcohol vapor to trigger its transformation back into a liquid state.12

The process works through the following principles:

Heat Removal: Condensation is the reverse of vaporization; for a vapor to return to a liquid, it must release the heat it absorbed during the boiling process. The condenser facilitates this by transferring that heat to the surrounding environment.21
Cooling Mechanism: To achieve this, the vapor is typically passed through a long tube, often arranged in a coil or compact shape, made of a heat-conductive metal like copper. As the hot vapor travels through this cooled tubing, heat escapes into the surrounding air or a cooling medium, such as water, circulating around the exterior of the tube.1
Liquefaction: Once sufficient heat is eliminated, the vapor loses the energy required to remain in a gaseous state and undergoes condensation, turning back into a liquid that is then collected as the final distillate.134