Your firm has taken the plunge. You’re going to open a London office. You know the locals drive on the wrong side of the road, and you’ve already discovered that they speak a different language. But there is one thing you’re unlikely to be prepared for — one crucial aspect of doing business in London that you won’t find on the management consultants’ checklists.

It is the locals’ drinking habits. Beer, wine, and (in the right circles) champagne are so much a part of business existence in London that the entire city seems at times to be engulfed in a fog, fermented and distilled, as dense as any rising off the Thames.