Everyone needs a human touch now and again, as Bruce Springsteen well knows. It’s the same with grapes. They need to be nurtured, protected, cared for, loved and caressed (OK, maybe caressed is going a little too far, but you get my point).

In the vineyard it is man who decides on location and aspect to the sun. It is man who manages irrigation and prunes vines to enhance concentration. And it is man who decides when it’s the right time to pick the grapes. Consistently tasting the berries and testing the sugar levels, the farmer decides on the exact day, and right time of the day, to start harvesting. The fun begins after harvest.

After all the time and work dedicated to growing the grapes, they are hand-picked or machined harvested before being placed into baskets and brought to the winery. For whites wines, white or pink grapes are used (the white Pinot Grigio, for example, is made from a pink grape of the same name). Most white wines don’t endure prolonged contact with the skins, so the grapes are crushed with the skin and juice being separated.

The juice goes into a settling tank, where the the undesirable solids sink to the bottom. When the winemaker is happy with acidity and sugar levels, the juice is ready for fermentation. This is the stage that the natural sugars in the fruit juice are converted to alcohol.

Typically white wine is fermented between 18-20 degrees centigrade in the Old World (Europe), and 12-17 degrees in New World countries (the Americas, South Africa, Australia, etc.) where there is a greater determination for fruit. Fermentation can last for anything from a few days to a few weeks depending largely on the temperature.

Red wine is fermented at higher temperatures (typically 25-30 degrees C), and as a result tends to occur more rapidly (usually 3-7 days). Red wine is made exclusively from red or black grapes as its the skins that give the wine its rich colour. Depending on the grape and the type of wine desired by the winemaker, the skins are left in contact with the juice during the fermentation process. More contact means more colour and richness, but can also mean more astringency (you know, the harsh, puckering taste you might experience in cheap or wines that need ageing?), so the balance is essential to getting the structure of the wine right.

After fermentation, both red and white wines are clarified to remove any remaining skins or other solids, and left to rest in steel or oak tanks. Much wine these days (in the particular the volume supermarket stuff) is bottled very soon after to provide quick sale and cash-flow for the wine-maker. Other wine is held back for ageing to develop more complex flavours. This is particularly true for wines aged in oak.

Some grapes suit ageing better than others. Most reds will benefit from some, and in the whites the likes of Chardonnay and Riesling are quite capable of lengthy ageing processes, particularly in the bottle.

So, the year of vintage printed on the bottle now gives you an indication of the type of wine you should expect to taste. The vintage is the year the grapes were harvested and the wine made. So a 2008 Sauvignon Blanc should be crisp, clean and straightforward, with lots of fruit to the fore, whereas a 1998 Chablis (made from Chardonnay) is going to be more complex, less fruity but with other complexities like yeast, or spice, or even a creaminess to the texture.

Happy, and more knowledgeable, wine-drinking this weekend.