Eating & drinking: The Champagne of teas

WHY WOULD a vertigo-prone, car-hating coward like me visit Darjeeling? Many of the roads are steep, winding tracks. It's 18 inches from the tyres to the precipice. There are no guard rails. For me it's vertigo- country; for tea bushes, Darjeeling is paradise. And that's why the hills were alive with the sound of my terror for a few days last spring. My guides, Adarsh and Sundeep Sethia, directors of Newby Teas Limited, had taken me to see where their favourite teas have their origins. Understanding tea is easy. All you have to do is devote yourself to the subject for a couple of decades. If wine is the most complex beverage on earth, tea is a close second. And Darjeeling tea is the most complex of them all. Don't have a decade or two to spare? Then here's a potted version.

Great tea grows at high altitudes, and the Darjeeling tea-growing district begins at 1,500ft; the best estates are far higher up. The bushes are the reddish-tinged Chinese variety - Camellia sinensis - which develops extraordinarily delicate flavours in the right conditions. They can survive low temperatures, heavy monsoon rains, and occasional droughts. They send their roots deep into the poor, well-drained soil, and can live almost forever - on the Ging estate, the average age of the bushes is 120 years. Old bushes, like old grapevines, produce the best quality.

They also give a relatively low yield, which is one of the many reasons good Darjeeling is so expensive. The average bush yields about 100g per annum, one third of the crop from tea bushes in the flat, hot plains where most of India's tea is grown. All these factors give Darjeeling a unique flavour. It's commonly described as "Muscatel", and some producers call their Darjeeling by this name. But when you taste a range, you also find flavours of peach, mango, papaya, citrus and even artichoke. This variety is highly prized by the discerning tea markets in Germany, Japan and Russia. It is not to be used as the British use tea: a tannic base for a milky drink whose primary purpose is to soothe the nerves. When people call it "the Champagne of teas", they're not far off the mark.

In tea gardens, as in vineyards, slopes make for high labour costs. A kilo of Darjeeling tea contains about 20,000 of the delicate shoots - two leaves and a bud - that are the only usable bits of the bush. The plucking - done by women with huge baskets on their backs - is slow and meticulous. And it's just one of numerous manipulations which determine whether the tea will achieve its natural potential. Plucked tea goes to the "factory" to be "manufactured". A woefully compressed account of this complex topic follows. The major steps apply in all teas except green tea. But in Darjeeling, the technical aspect is especially important because the raw material is so delicate. Bad manufacturing can ruin great tea.

After plucking, Darjeeling tea is withered: dried at about 90F for 12 to 16 hours to reduce water content, initiate various biochemical changes, and prepare the leaves for rolling. Rolling is done in machines comprising a convex pressure plate on a concave pan. It curls the leaves and ruptures cell membranes; this takes between 60 and 90 minutes. After rolling, the tea is spread out in perforated trays for what's usually called fermentation. The process is actually oxidation, and it takes anything from 90 minutes to four hours. This is when the flavour and colour-forming compounds develop; it is what makes tea leaves into tea. Finally, the leaves are fired - heated on trays at about 240F for 20 to 30 minutes. Firing stops oxidization and lowers the water content to 2 to 4 per cent. The leaves are now ready for sorting into grades. Whole leaves and buds (tips) are the only desirable size for the finest Darjeeling. Smaller particles (brokens, fannings and dust) are used in inferior blends and tea bags.

The bad news about Darjeeling tea is that there's hardly any of it: about 9 to 10 million kilos a year. Sounds like a lot? Not compared with Assam, India's other premium-quality tea-growing area, which makes about 525 million kilos; or with total world production of about 2.5 billion kilos. And there's robust demand for Darjeeling. The complex interaction between terroir and human manipulation is what makes one Darjeeling tea different from another. Tune in next week for concrete examples of how this interaction plays out in the caddies of Darjeeling you can buy in Britain. And leave the milk in the fridge.