Most of us are impressed by people who can get the wine correct at a blind tasting, and secretly wish we could do the same. How do they do it? Considering the large number of producing countries and regions, grape varieties and blends, this might seem a daunting if not impossible task.
Most tasters normally start by eliminating half of the world, by going down the Old World-New World route. Because of tradition and winemaking technique, Old World wines tend to be more restrained. Reds usually have savoury characters while whites may have a hint of saltiness, some might say "minerality".
New World wines are usually more fruit focused and forward. This is true even for aromatic grapes such as riesling. A German riesling is more subdued than one from the Clare Valley. So if the wine smells of abundant fruit, chances are it is likely to be from the New World.
To get closer to the origin, one needs to take geography into account. Wines made in cool or mild climates are likely to have a lower alcohol level and higher acidity than those from warmer regions. This is because in warmer conditions grapes ripen faster, accumulate more sugar and lose acidity faster. Sugar is converted to alcohol during fermentation, so wine from hotter areas such as southern France will have higher alcohol levels than cooler Burgundy.
There are exceptions, however. Grapes grown in a continental climate - hot days but cool nights - have both high sugar and high acidity. Don't forget that water and altitude play a part. The ocean has a cooling effect on coastal vineyard areas in Chile, California and Stellenbosch, but brings a milder climate to Bordeaux, while every 100 metre increase in altitude sees the temperature drop by 0.6 degrees. Keep this in mind and you can narrow the field down.
Say you are given a delicate wine with fresh acidity and moderate alcohol; it is likely to be from a cool climate Old World region. A wine with pronounced fruit characters but moderate alcohol is likely to be from a coolish New World region, maybe Margaret River, or high altitude vineyards in Chile.
Getting excited? It's time to study now. You don't need to be a brilliant taster but you must be knowledgeable if you want to get the wine correct. The wine's structure is most important. Some grapes, such as nebbiolo, touriga nacional and cabernet sauvignon, are always high in tannin, but the first two will also have higher acidity. Merlot, malbec, pinot noir and zinfandel have both medium tannin and acidity. Grenache, gamay and barbera have low tannin levels but the latter two have much higher acidity than grenache.
Colour also gives some hints. For example, what is a red with pale colour and high acidity? It could be nebbiolo, sangiovese or pinot noir, but if the tannin is high then it can't be pinot noir. Now, look at the alcohol. If it is over 14 per cent, it is highly likely to be nebbiolo because Piedmont (where nebbiolo is grown) has a more continental climate than Tuscany - home to sangiovese.
Take another example. A near opaque wine with moderate acidity and lush black fruits is probably a New World shiraz, merlot or malbec. If the tannins are obvious but round, and there are jammy and spicy notes, I would put it as a shiraz above the others. And if the alcohol is 14-14.5 per cent? Very likely a shiraz from the Barossa.
White wine is similar. It doesn't have tannin, so acidity and alcohol level are the key factors. White grapes can also be categorised into aromatic ones (sauvignon blanc, riesling, viognier, gewürztraminer, muscat); or neutral ones (chardonnay, pinot blanc and semillon); or even semi-aromatic grapes (chenin blanc, pinot gris and albarino). So an aromatic wine with crisp acidity could be a riesling or sauvignon blanc, but if it has a purity of fruit and alcohol of 13 or 13.5 per cent, it is possibly a New World sauvignon blanc. Alsace riesling could have 13 per cent alcohol but it would be more mineral rather than fruit focused.
However - and this is exactly what makes it so interesting - wine is not that black and white. With climate change, flying winemakers and the exchange of winemaking techniques, we are now seeing Old World wine styles made in the New World and vice versa.
Some Bordeaux reds, especially those from riper vintages, are more fruit-forward with rounder tannins than the classic ones. The Kumeu River Hunting Hill Chardonnay from New Zealand is made in a Burgundian style which, in blind tastings, has fooled many a wine professional into believing it is a premier cru Burgundy.