If you’ve ever bought wine in Lidl, the chances are that your choice of bottle has been influenced by Richard Bampfield. He’s the guy who assigns the scores to selected wines on the supermarket’s shelves. He’ll give 90 out of 100 to a Sauvignon Blanc that costs less than seven quid, and 92 points to a Chardonnay under £9. And he’s very open about how he does it.