Turn up unannounced at any of the world's great wineries and, more often than not, as a friend of TIM ATKIN MW can testify, you will be greeted with a polite 'Non, Monsieur'. Atkin understands their point: 'If the likes of Ptrus, Vega Sicilia or Domaine de la Romane-Conti gave tastings to every passing wine lover, they'd run out of booze in weeks.'