This is a little out of sync, but I need to brain-dump and Pob will shortly be posting some more up to date details of our trip.
I like the Argentinian way of life, but apparently in Argentina the adults drink more fizzy drinks than they do wine. This is not something Pob and I have been trying to emulate over the last few months.
The following grape growing info comes with a big health warning - most of it was gleaned from poorly understood bodega (vineyard) tours in Spanish or occasionally pretty sketchy English. Also, it's taken me a while to get round to writing this but maybe that means this will be the mature, concentrated version.
Wine growing guide
Start with lots of sunshine which you can maximise by planting your grapes in East-West orientation for all-day exposure. This apparently makes the skin thicker (the grapes' way of making their own sunblock) and more skin means more flavour from tannins and such.
Start with a dry atmosphere (high altitude helps), with minimal rainfall but readily available water from snow melt. This allows you to vary watering during the growing season - limiting it before harvest to concentrate the juice and who wants watery wine?
For organic grapes, a sunnier, drier atmosphere means you'll have far fewer pests. Lavendar is useful because bugs like it more than they like grapes. Also plant roses as a disease warning system because they're much more sensitive than vines are, acting a bit like canaries for miners.
Apparently birds don't like grapes but you may want to use nets to protect your fruit from hail stones.
To go one better than organic grapes, why not try biodynamic techniques? One bodega testing this out explained they were timing pruning and harvesting by the phases of the moon. The theory is to prune during new moon, when gravitational pull keeps all the nutrients in the roots, then harvest at full moon so maximal gravity draws the goodies to the grapes. Unfortunately the grapes are still a couple of years off being certified so there's no wine to try yet.
Even once the biodynamic stuff is certified, it might not be really good for decades because wine is said to be better from vines-of-a-certain-age. The average plant can last ~150 yrs and I seem to remember the best years are 80-110 years old. In another bodega we were told you can achieve the mature vine effect simply by taking a cutting from an older vine so the new vine is a clone of the old. This will not only start producing great grapes straight away but also last ~150 years. Sounds too good to be true to me - I don't know why everyone doesn't do it.
In the Southern hemisphere the harvest usually happens in February or March. However for a 'tarde' desert wine, the grapes are allowed to mature on the vine for longer increasing their sugar content.
When harvesting, make sure the grapes don't burst because this would start fermentation. Warmer (and therefore faster) fermentation should be avoided unless you want cheap plonk. Many bodegas control fermenting temperatures with cellars, or refrigerated tanks but we visited one champagnery that ferments the grapes in a cave!
To start fermentation you need to mulch the grapes. Most wines don't need added yeast because it exists naturally on the grapes themselves. Remove the bits (seeds and skin) straight away for white, remove afer a day for rose, or a couple of weeks later for red. After fermentation you leave the juice in a tank for several weeks to develop.. By this stage you could bottle your young wine now, or if you think your grapes are up to it and you want a better (more pricey, longer lasting) wine, move it to oak barrels. The barrels should be made from French or American oak, each of which imparts distinctive flavours to the wine through tannins. American oak is cheaper, imparting flavour faster and tends to provide notes of tropical fruits or vanilla, while French oak takes longer but is said to be of higher quality providing aromas like chocolate, coffee, mushrooms and tobacco.
While the wine is in the barrel some will evaporate, concentrating the flavours and upping the alcohol content. The tannins from the barrel also act as a preservative. Grape skins also contain tannins although the amount depends of the grape variety. This means that wines made from Cabernet Sauvignon, which is full of tannins, last longer than Malbecs, which have hardly any. Also, since white wines are separated from their skins right at the start, they just don't last as long as reds.
Wines oaked for a long time (e.g. 2 years) are more flavourful, alcoholic and can be kept for years longer, improving with time - up to a point. Natural cork also adds preservatives and flavour (although I gather this is controversial) and if using natural corks you should leaving the bottles on their side in a cool dry place for a few months. If you happen to have a spare 19th century fermentation tank, this would be ideal.
We are now in La Junta, a small town on the Carretera Austral in Chile. This is the road which we will take for the next 900km south. If the first few days are anything to go by then its going to be quite a trip! We left the small welsh town of Trevelin on the 27th, with company! We happened to be staying in the same hostel as an English couple, Hugh and Pauline, and an Austrian, Nadja. They had met a few days previously and were heading in the same direction as us, so we joined them. It's lovely to have some company from home and to be with English speaking people for the first decent amount of time since Lou left us in November!
