Glossary

V

VDK (vicinal diketones) - Diacetyl (2,3-butanedione) and 2,3-pentanedione are important contributors to beer flavor and aroma. Sometimes these two ketones are grouped and reported as the vicinal diketone (VDK) content of beer.

VENTING - Once cask conditioned ale is delivered to a pub it must be set up in its serving position and then left undisturbed until the cask is empty. The publican must also "vent" the cask - allowing the cask to breathe and secondary fermentation to take place. Secondary fermentation of the beer in a closed cask ensures that the beer becomes completely saturated with CO₂.

VISCOSITY - Viscosity is a measure of the resistance of a fluid to being deformed by either shear stress or extensional stress. It is commonly perceived as "thickness", or resistance to flow.

VITREOSITY - Vitreosity, an inverse of mealiness, is a measure of malt's glassiness.

VOLATILE - Readily vaporized especially esters, essential oils, and higher alcohols.