pressure infusion

is a process for rapidly infusing flavors from a solid into a liquid and is one of several techniques that can be used to introduce new flavors into a spirit. In pressure infusion, ingredients are placed into a sealed container that is pressurized using a gas—usually nitrogen or nitrous oxide—with low solubility in the liquid at atmospheric pressure. The increased pressure causes the gas to dissolve into the liquid and forces the liquid into the solid material. When the container is subsequently decompressed and the gas quickly comes out of solution, the expanding bubbles rupture the cells of the solid material, and a rapid infusion into the liquid is obtained. This technique can result in a near-instantaneous infusion in contrast to traditional methods that might require multiple hours or weeks, and thus can be particularly useful in preserving “bright” herbaceous and “green” flavors that ordinarily would become dull or muddy over the course of a lengthy traditional infusion. See infusion.

Notwithstanding these advantages, pressure infusion is generally used more in bars or at home than for industrial spirits production. While it is fast and thus useful for making à la minute the sorts of infusions that are common in the more advanced, technically oriented modern bars, compared to long-term infusion techniques, it is less efficient at extracting flavor components, and larger quantities of the solid ingredient are required to achieve results of comparable intensity. In addition, some flavor components are less readily extracted via pressure infusion, which may result in different flavor characteristics than those produced by more traditional methods.See also cocktail renaissance, molecular mixology.

Arnold, Dave. Liquid Intelligence. New York: Norton, 2014.

Simpson, Richard J. “Disruption of Cultured Cells by Nitrogen Cavitation.” Cold Spring Harbor Protocols, 2010.

By: Samuel Lloyd Kinsey