Wine making is as least as old as human civilisation. Wine made from grapes from Vitus vinifera (wine-bearing) species are generally agreed to originate from what is now Georgia about 3,000 BC. The Ancient Egyptians left detailed accounts of vine growing and wine making, although not much about how their wines tasted. The Romans are credited with the spread of Vitus vinifera through Europe about two-thousand years ago to what are now famous wine regions. Today with the exception of Antarctica vines are grown and wine is made on every continent on earth.
Vines perform best within a band of latitudes approximately between 30oN 50oN and the mirror image for the southern hemisphere, 30oS 50oS. Look at a map of the world and all the famous wine producing areas fall into these latitudes. The reason is partly climate as to produce grapes suitable for quality wine making it is generally agreed that vines require a period of dormancy. In the appropriate latitudes and the on-set of winter, cooler temperatures encourage the vine to shut down and the sap falls from the plant above ground to the roots. Dormancy protects the plant against frosts and enables the plant to conserve energy in preparation for the next growing season. As temperatures rise with the on-set of spring the plant awakens, the sap rises again and the vine goes into its busy period of sending out shots followed by flowering, budding, and the final result ripe fruit.
In Kenya seasons are more based upon rainfall than temperature. Kenyan farmers do not talk about the winter, but the short-rains or the long-rains. Kenya straddles the equator and with its tropical climate vines can grow all year round. For producing table-grapes this is not necessarily a disadvantage, but for wine making it is none to good. To make good wine, wine makers search for grapes that are small with concentrated flavours. This is why quality wine producers throughout the world tend to constantly thin their grapes by picking and discarding berries to keep yields at relatively low levels and quality high.
Vine growers in Kenya and other tropical countries have developed techniques to cope with unfavourable climatic conditions. To an extent Kenya has advantage in the form of high altitudes. Kenya’s few vineyards are all at altitude mostly in the highlands above about 1,500 metres. This is beneficial as the altitude provides cooler daytime temperatures than the latitude normally would dictate that prevent the grapes becoming burnt or to hot. Even at altitude though, in Kenya temperatures seldom drop low enough and for long enough to encourage the vines to enter dormancy.
To encourage dormancy or at least to restrict the vine from continually fruiting tropical grape producers tend to double prune. This involves pruning right after harvest usually in February and then again in September. Additional fungicide spraying is also deployed mostly to militate against disease that is more likely to develop in the relatively wet and warm conditions found in Kenya. Some wine makers are experimenting with the idea of applying a hormone to the vine to in effect kid the vine into entering dormancy. To waken the vine from this induced dormancy period, grape growers are also experimenting by applying hydrogen cyamide (Prussic acid). An advantage of this application is that as well as wakening the vine it also encourages the uniform setting of fruit. This technique is used fairly extensively for grape production throughout the world particularly in the New World. Uniform fruit setting has a number of advantages not least being that there is more likelihood of achieving uniform ripeness at harvest. This means that mechanised picking can be deployed, which has the advantage of usually being more cost effective than hand-picking, which cannot differentiate between ripe and unripe fruit.
With modern techniques of vine growing, including on the near horizon the possible benefits of genetic modification, could it be that the tropics including Kenya will offer a future of good or even great wine production? Probably not is the answer, but on the other hand some would disagree and argue in depends on the time frame. India for example is storming ahead in terms of vine planting and wine production mostly within its tropical regions feeding the ever-burgeoning demand of its middle classes. Brazil’s tropical regions are also producing more and more wine. It is at least whimsical to consider that perhaps in twenty-years or so a Kenyan wine may bear comparison with a European first-growth cousin. I will keep you posted.
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