Canberra International Riesling Challenge chairman Ken Helm said there would be plenty of opportunity for the public to get involved in the event, which he said was not "just a wine" show.

Events include master classes and seminars on Friday showcasing wines never seen in Australia before, an awards ceremony on Friday and a public wine tasting of all 500 Rieslings on Saturday.

"This not only promotes riesling but it promotes Canberra to the world, because the winners take the awards back and display them in their tasting rooms so people from all around can see them," Mr Helm said.

The seminars and master classes on Friday aim to promote the breed of grape as well as help growers improve their vineyards and wineries.

Chair of judges, John Belsham, said the panels sometimes had a difficult job in scoring the wines.

"We don't just say, I scored it this and you scored it that and we'll add them up, we have discussions about each wine and it's unfortunate that we have to distil all of the discussion we have to a score," he said.

"We have to be very conscious as judges that this is only our opinion, and the public may think differently, but I think that's the fun of it."

Mr Belsham will be joined by critics from Australia and around the world including Jim Trezise from the United States and Romana Echensperger from Germany.

Mr Helm, a winemaker himself, sees a bright future for the Riesling Challenge and for the enormously diverse wine.

"The most entries we've had was 512 so this year is pretty close to that and I predict that in future years we'll be getting up to 1,000 entries," he said.

"I've always believed Riesling is one of the wonderful grapes and it hasn't seen its full potential yet."

There are even hopes for a roadshow of the top rieslings from the challenge to be showcased around the world.

Details and tickets for the Canberra International Riesling Challenge can be found at www.rieslingchallenge.com.