You'll need a proper glass for nosing and tasting the whisky. A sherry glass (also called a copita) is perfect. It has a stem and is tulip shaped -- if you can't find one, use something similar like a snifter. A wine glass will do, as long as it has a stem.
Don't use a highball, a shot glass or a so-called "whisky glass."
"You want to capture the whole aroma," says Richard Paterson, Whyte & Mackay Master Blender. "The shape of the glass, the way it's shaped like a tulip, will force the bouquet into one area -- your nostrils. How you approach the whisky will greatly affect how accurately you are able to assess it."
Prepare the glass
Pour a tiny bit of whisky into the room-temperature glass. Swirl and tilt the whisky around in every direction to coat the inside of the glass, then toss it out. It's important to add a swirl as you toss it.
"You want to make sure the lip of the glass is absolutely, totally clean," says Paterson.
Then grab hold at the bottom, at the stem. This prevents your body heat from transferring to the drink during tasting, and it's very important.
One ounce or so is enough for a taste. Remember, only hold onto the stem from now on.
This is called "nosing" the whisky, and Paterson recommends you break it down into three steps.
Step 1: Stick your whole nose in the glass and gently sniff it. You'll get a big hit of alcohol vapor. Now pull it away and have a look at the whisky. Roll it around and take note of the color.
Step 2: Wait two seconds, then go back to it.
Step 3: Go back a third time. This time, bury your nose into the lip of the glass, and roll the glass from one nostril to the other.
"You need to get to know the whisky, communicate with it, learn about its character." Paterson says. "Look at it, talk to it, really try to experience it."
Add a dash of distilled water and reduce the whisky down to about 35 percent alcohol. Adding the water opens it up and makes it more approachable.
Paterson says for younger whiskies (12 years or younger) water is always advisable. For whiskies 15 years and up, don't add water before you first taste it. But no matter what the age of the whisky is, if it still bites you when you take a sip, it's too strong for you and you should add water a little bit at a time.
Don't use sparkling water. Any good still water will do, but distilled water is best. Don't use ice, it will only mask the flavors.
Take a small amount of whisky -- just a sip -- into your mouth and move it around.
Start by putting the whisky in the middle of the tongue, then under the tongue, then back in the middle of the tongue. Keep it there a few seconds and assess the flavors, then let it go down. As it goes down, the tongue will reveal more interesting flavors.
Paterson says to let the flavors linger for a good 20 or 30 seconds at least.
"Whisky has an inner world, and you must give it time to show itself," he says.
Always take a second taste.
"Little different layers will start to open up to you with the second taste"
Adapted from http://howto.wired.com/wiki/Taste_Whisky