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Venus Climate Studies

  • Venus Climate Studies

    What makes tea grown at high altitudes so prized for its refined qualities? When one hears the words "Tea" and "Altitude", one tends to think immediately of Darjeeling - situated in the foothills of the Himalayas, as having the highest tea gardens in the world. In fact, the tea gardens in Darjeeling rise to about 6500ft, whereas in Nuwara Eliya district in the Central Highlands of Ceylon, tea is grown up to 7500ft and many of the other famous tea growing regions of the world also have tea gardens situated at very high altitudes, which produce particularly well regarded teas.

    The traditional view is that at higher altitudes, the Camellia Sinensis plants grow more slowly due to the cooler climate and this is responsible for the improved flavour. That may be true, but one could then ask why tea is not grown at lower altitudes in slightly more temperate regions of the world, where the climate follows a similar temperature pattern to the high tea garden regions in Darjeeling and other renowned tea producing regions. This is in fact the case in Japan where many of the tea growing regions are at a very northerly latitude for tea cultivation. The tea gardens there are mainly below 2000ft. There are higher gardens with some going up to 2500ft and these teas are recognised as having a unique quality, but they are not the most famous or expensive teas in Japan.

    Although there is no clear and definitive answer to the altitude question, it can be better understood by looking at all the main factors in tea cultivation, and how they are affected by altitude. The amount and frequency of rainfall, the quality and humidity of the air, the amount of sunlight, soil composition, depth and drainage are all important factors in tea cultivation. In Darjeeling, the rainfall is described as intermittent with good sunshine and moist mountain mists. The soil is rich and the hilly terrain provides good natural drainage. Also, the tea gardens there are in some cases over 100 years old and the shrubs have been selected over many generations for the best quality crop in that unique environment. The unique flavour of tea from these bushes is again enhanced by only picking the best leaves, which gives very low yields compared to most lower elevation tea gardens. Darjeeling tea is first processed by withering, i.e. removing the moisture from the freshly picked leaves. This is done very carefully, using hot or cold air depending on the weather conditions when the leaves are picked. This is often said to be the most critical part of Darjeeling tea production. After withering is the fermentation, where the freshly picked tea is allowed to oxidise naturally for a few hours before firing. For Darjeeling tea this is done in a fermentation room which is open to the cool mountain air which mingles with the leaves as flavonols oxidise, giving a final contribution to the unique Darjeeling muscatel flavour.

    Just how important each of these factors is in giving the final Darjeeling product its unique qualities is not known for sure. Perhaps we will never know. Scientific studies could be done to determine the effect of changing any part of the cultivation and production of high altitude teas, but the combination of many factors that contribute to the overall quality of these teas is probably very complex, even if it could be described in purely scientific terms. As a first step to a deeper understanding of altitude and other factors that contribute to quality tea production we propose to gather as much information about a sample of tea gardens where tea is grown at altitude. We will look at tea gardens in Darjeeling, Sri Lanka, and at Munnar in south-west India. We will also look at tea gardens on the Jubuzan mountain in Uji prefecture in Japan. Although these gardens are only at an altitude of about 2500ft this is very high for Japanese tea cultivation and they produce a unique tea known as "Uji Sencha Jubuzan".

    Altitude is also an important factor in coffee cultivation. In Colombia for example, the ideal elevation for producing premium coffee is between 4000ft and 6000ft, where the mountain air, soil, sun exposure and precipitation patterns combine to give Colombian coffee its famous light and fruity qualities. In Ethiopia also, coffee is grown at a range of high altitudes, from around 4000ft up to at least 8000ft for some varieties. As is the case for Colombian coffee, the altitude factor is important but in general there appears to be a less direct relationship for coffee between the quality of a crop and the altitude of its cultivation, than is found in tea production.

    Cocoa production usually takes place at much lower altitudes than either tea or coffee production, due to the fact that the cacao trees which produce the cocoa pods require constant tropical temperatures and humidity. However, the elevation of cacao tree plantations is still of some importance. The tree may have had its origins in the foothills of the Andes mountains (several thousand years ago) and it is often said that cacao plantations require an elevation of at least 200ft. The town of Ciao in Venezuela is famous for production of very high quality chocolate. Although it is situated on the northern Venezuelan coast it is at an altitude of over 800ft in a bay surrounded by the Venezuelan cloud forest mountains.

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