When we wrote Wine Grapes with its detailed profiles of the 1,368 grape varieties we could find that produced wine in commercial production, we always knew that we'd probably set ourselves an impossible task in trying to identify every single candidate worldwide. We'd certainly like any second edition to be even more comprehensive, so in the foreword we ask readers to send any suggestions for other grape varieties not included in the book to email@example.com.
We've had quite a bit of response and many of the varieties suggested have turned out to be synonyms for varieties that are in the book or the wines made from them were not in commercial production before 2011, when we finished work on the text. However, there have been some excellent suggestions, ones that have had us metaphorically kicking ourselves.
In an effort to encourage more suggestions, our co-author José Vouillamoz (@JoseGrapes and pictured here by Sedrik Nemeth) has devised a competition called Not in Wine Grapes which has its very own hashtag on Twitter #NotInWineGrapes and is described fully here.
The first 10 people to draw to our attention grape varieties making wine commercially before 2011 that are not in our book will be sent a bottle of fine wine from the Valais, home to so many top-quality wine grapes, generously donated by Les Vins du Valais.
Best of luck!