[LantzALot]

(From your link;) Once an AVA is established, at least 85% of the grapes used to make a wine must be grown in the specified area.

A son-in-law works for one of the big-name wineries in Napa Valley. I believe he told me that they require 90% of the grapes to be from Napa to qualify for the appellation.

[quantim]

It depends on how specific the designation so it could be a little confusing.

Some vintners may designate a higher internal percentage than what is required.

American Viticultural Area/Appellation of Origin Matrix