Madeira, a small miracle

I'm not just talking about the rule-breaking way that it's made, its indestructibility or its miraculous ageing potential. I'm not just talking about the acid–flavour structure which makes sweet wines taste dry and high-alcohol wines taste super-fine. I'm not even talking about the breathtaking complexity and beauty in many of these wines, which could break the hardest heart. I'm talking about something rather more prosaic.

It's almost impossible to convey the micro scale of viticulture on...