Every so often Jancis and I are invited to a tasting I find hard to resist: a selection of some of the most obscure grape varieties and wines collected by a certain wine-loving London resident. Thanks to his day job, he's a frequent flyer, and he seems to enjoy truffling out these rarities almost as much as he enjoys tasting them and sharing them with his friends. It's rather like the challenges and the pleasures we enjoyed when researching Wine Grapes. I have never seen quite such a well-thumbed copy of the book as in this wine lover's house...