Claude and Lydia Bourguignon are soil microbiologists in high demand. The couple work with some of the world’s leading vineyards – digging deep to investigate the soil fauna and root systems of the vines. It’s impossible to produce a wine of terroir without a healthy soil, they say, and reject the trend for investing heavily in the cellar with scant regard for these complex ecosystems. “It’s stupidity to have a fantastic winery and dead soil - for us it’s totally ridiculous.”