What process is used to increase the alcohol concentration in spirits?

The process used to increase the alcohol concentration in spirits is distillation. Distillation works by taking advantage of the different boiling points of the components in a liquid mixture. In the production of spirits, the initial liquid is typically a fermented mash or wash containing alcohol, water, and various other compounds. When this mixture is heated in a still, the alcohol evaporates first due to its lower boiling point compared to water. The vapor is then collected and cooled back into liquid form, resulting in a beverage with a higher concentration of alcohol than the starting material.

Fermentation is a vital step for producing the alcohol in the first place, as it involves yeast converting sugars into alcohol and carbon dioxide, but it does not increase the alcohol concentration in a liquid. Filtration is primarily used to clarify spirits by removing impurities and solid particles but does not affect the alcohol content. Carbonation involves the introduction of carbon dioxide gas into a liquid, which results in fizz but has no direct impact on increasing alcohol concentration. Thus, distillation is the key process that elevates the alcohol content in spirits.