Posted in Kafevend Blog
'There's gold in them thar hills', as the saying goes, and it's certainly no less true of camellia sinensis, better known as the tea plant. Many of the world's finest teas are grown at high altitude, but what is it that gives these teas such an edge as far as flavour is concerned?
Tea does better when the difference between day and night time temperatures is significant, so the variation provided at higher elevations proves useful. The cooler nights mean that the rate of growth is slowed down and this factor appears to be instrumental in giving the tea plants time to fully develop, resulting in more intense and complex flavours. Hilly or mountainous areas are also subject to greater rainfall, another key component in cultivating tea, which requires at least 1500mm annually. Away from lowland areas human population is less dense and the road system less significant, meaning that the tea is being grown in cleaner, fresher air. When these factors are combined with a soil that's rich in quality it's bingo time!
Naturally, these teas are more expensive than most and not merely on account of their flavour profile. The fact that conditions cause the tea to grow more slowly means that less tea is farmed overall than at lower levels. It's also generally harvested by hand and this factor, coupled with greater transport challenges, have an additional effect on the cost of the finished product. Moreover, there's simply less land available for higher altitude tea enterprises.
Unsurprisingly perhaps, Darjeeling, often lauded as the champagne of teas, is cultivated on the southern slopes of the Himalayan foothills, at altitudes ranging from 800 – 2000m, with the loftiest sites generally producing the very best of the range.
Here's a question to ponder then, if the finest teas are farmed at height, are mountains a good place to enjoy drinking them? Most of us tend to assume that tea is best brewed with freshly drawn boiled water, so it's worth pointing out that while water boils at 100ºC at sea level, it starts boiling at lower temperatures the higher up you get. The science behind this phenomenon is down to air pressure; air is thinner higher up and so it doesn't exert as much pressure, meaning that it takes less energy for the water to come to a boil, causing a reduction in the boiling point. At 800m, for instance, it boils at 97ºC, at 2000m – 93ºC. So on the face of it we might assume that the answer to the question is no, you won't get such a good cup of tea on a mountain. However, while most of us here in the UK are sticklers for a scalding hot cuppa, a full 100ºC boil isn't really recommended for anything other than black tea, and even then it's a moot point when it comes to the more delicate black teas such as Darjeeling. As for some green teas, ideally there should be no more than a faint wisp of steam before the brew is made.
When all's said and done then, the best place to enjoy the finest high altitude teas could well be in the place they were grown, and failing that, don't take your eye off the kettle!