From: Windows On The World- Complete Wine Course by Kevin Zraly, 1999 Edition
Use this simple method as a guideline for tasting wine…
Take a mouthful of wine and 'chew it'; take in some air to release the volatile compounds, and swallow the wine. Resist judging the wine for the first 15 seconds but start analyzing it.
0-15 seconds: If there is any sugar/sweetness in the wine, you will experience it in the first 15 seconds. If there no sweetness in the wine, the acidity is usually at its strongest sensation during the first 15 seconds. Also look for the fruit levels of the wine.
15-30 seconds: After the sweetness or acidity look for the fruit sensation. After all, this is what you are looking for! By the time you reach 30 seconds, you are hoping for a balance of all of the components. At this time you should be able to tell the weight of the wine. (Is it light, medium or full-bodied?) Also think about the types of food you would enjoy the wine with.
30-45 seconds: Not all wines need 30 seconds of thought. Lighter style wines such as Riesling will usually show their best at this point. For example the fruit, acid, and sweetness of a good Riesling should be in harmony from this point on. For quality red and white wines the acidity should now blend with the fruit of the wine. At this point, you should see balance in the components.
45-60 seconds: Big wines like California and Australian Cabernets, big Italian reds like Barolo, classic red Bordeaux and white Chardonnays will continue to reveal character and balance. The later tannins and fruit should still be in balance with the early acidity. If the tannin is still overpowering the fruit the wine may need more aging.