Unlike most European appellations, an AVA specifies only a location. It does not limit the type of grapes grown, the method of vinification, or the yield, for example. Some of those factors may, however, be used by the petitioner when defining an AVA's boundaries.
Current regulations impose the following additional requirements on an AVA:
Once an AVA is established, at least 85% of the grapes used to make a wine must be grown in the specified area if an AVA is referenced on its label.
State or county boundaries, such as Oregon or Napa County, California, are not AVAs, even though they are used to identify the source of a wine. AVAs are reserved for situations where a geographically defined area has been using the name and it has come to be identified with that area. There are hundreds of AVAs, ranging in size from 26,000 square miles to less than a square mile.
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