Abbreviation for "American Viticultural Area" (also "Approved Viticultural Area"), the appellation system commonly used in the USA. It was introduced at the insistence of Californian grape growers in particular. This was because the classification system by climate zone developed in California in the 1940s had proved to be inadequate. From 1970 onwards, all US states were analysed by the then BATF (now TTB = Alcohol and Tobacco Tax and Trade Bureau) on behalf of the US federal government with regard to their geographical characteristics. This included, for example, the suitability of certain regions for a particular grape variety. In 1978, some geographical areas were then classified for the first time, creating the conditions for an origin system based on the French Appellation d'Origine Protégée. The first systems, which were still very inconsistent, were based on political state or county borders.
The glossary is a monumental achievement and one of the most important contributions to wine knowledge. Of all the encyclopaedias I use on the subject of wine, it is by far the most important. That was the case ten years ago and it hasn't changed since.Andreas Essl