Growing Wine Grapes– Viticulture

Climate

Grape growers aim to pick grapes at the optimum moment when their ripening provided the perfect balance of acidity and Sugar (NB the sugars don’t end up in the final wine because they turn into alcohol during fermentation but their presence in the picked grape affects the final flavour of the wine. Obviously sweet wines retain their sugar – that’s what makes them sweet)

Deciding exactly on that optimum moment is the true art and it will differ according to the grape type and the climate in which it is grown. Lets start with climate. German grape growers generally have a cool climate – ie they do not have much sun and their grapes ripen less than grapes in, for example, Australia which has a much warmer climate and tons of sun. Obviously German grape growers know this because they are not idiots and so they go for grape varieties that require less sun to ripen them. Hence they generally use white grapes such as reisling and muller thurgau which make good acidic white wines. (Indeed, some areas of Germany are so cold that grape growers add sugar to their grape juice so that when they ferment it there is enough sugar to produce a decent level of alcohol). Australian growers are also not idiots and they go for grapes that respond to all the lovely sun they get – notably chardonnays and shirazes. This is not to say that you cannot grow reislings in Australia (they do and they are very good) merely that, on the whole growers think they get better and more interesting wines from particular grapes in their particular climate.

Of course some grapes happily grow in both climates and you get interestingly different styles of wine from each. A good example is chardonnay. This is the classic grape of Burgundy in France where it produces everything from steely, acidic and mineral Chablis in the colder north to buttery creamy honeyish classic burgundys in the slightly warmer southern areas of that great wine region. If you take the chardonnay into even warmer southern climes – eg Australia and Chile – the honey remains but you get a much greater expression of tropical fruit flavours such as peaches and lime. This difference owes a great deal to the climate – the fruit flavours in Australian and Chilean chardonnays come about because of the ripening effects of the sun. Similarly Chablis retains its acidic steeliness because it is in a colder climate.

Now pedants among you will be able to find examples to contradict this – eg nice steely Chablis style chardonnays from Australia. This is because A) I am generalising, B) they grow them half way up a mountain where it is a bit cooler C) You wont find very many of them.

Soil

So that’s the basics of climate but the flavour of a wine also owes a great deal to the soil it is grown in. The French love soil – they call it ‘terroir’ and the purists among them argue that a wine is (or at least should be) a perfect expression of its terroir. Ie all the wine maker is doing is taking the flavours inherent in the soil in which the grapes are grown and transferring them into the wine with as little alteration and manipulation as possible. Actually ‘terrior’ means something a little more complex than just soil – it also includes the climate and morphology (more commonly called aspect) of a given vinyard, but the basic point is the same – that wine is a product of nature and the winemaker is simply there to ensure all that natural flavour finds its way into the bottle and them into your mouth. Different soils impart different flavours to the grapes. It makes sense because the vines, as they grow, suck up water form the soil and this will contain lots if stuff that was in the soil. This can be refreshingly straight forward – limestone will generally impart limestone flavours into grapes. Chalk will similarly reveal itself in the flavour of a wine. The mineral aspects of a wine’s flavour will come from the minerals such as lime and chalk in the soil.

Another point about soil is that grapes don’t like soil that is too fertile. Grapes like it tough – they want to have to put down deep roots and really search out the goodness. Otherwise they get lazy and produce wine that hasn’t bothered to make the effort to really suck up all the interesting stuff in the soil.

On to making the wine.