I am not a big drinker, but I enjoy a good single malt whisky on occasion. What is single malt whisky, you might ask, and what is the different between whisky, scotch, single malt whiskey and scotch single malt? I am getting that question often, and I have compiled a page trying to explain it as good as I can.
My interest in single malt whisky started back in 1994 (if I remember right) when I picked up a bottle of Glen Moray at London-Heathrow Airport during a business trip. The tax free store had samples and I liked this particular one, so I purchased a bottle. It was the first one, but would not be the last.

Single malt, vatted and blended
Single malt whisky is a whisky made from only one type of malted grain and distilled at one particular distillery. Single malts are typically associated with Scotland (Scotch single malt), though they are produced elsewhere, notably in Ireland and Japan. Whiskey is simply the Irish (and North American) spelling of whisky.
There is even a Swedish whisky destillery, Mackmyra, founded as late as 1999. I have actually tried some of their whisky, and even if it is young it is very good. I can't wait for it to mature even more.
To be called a single malt whisky, a bottle may only contain whisky distilled from malted barley produced at a single distillery. Scotch single malt whiskies are classified after the district in Scotland where the distillery is located (see map to the right, click on each region to find out more, courtesy of Wikipedia).
This is what I most frequently drink, and I will list my favourites later on this page.

If the bottle is the product of single malt whiskies produced at more than one distillery, the whisky is called a vatted malt, blended malt, or pure malt. There are not many of these, but one of the most well known is Johnnie Walker Green Label. Since 2009, they have to be labelled "blended malt" according to UK Government guidelines.

If the single malt is mixed with grain whisky, the result is a blended whisky. Premium blended whisky contains up to 40 or 50% single malt, while the inexpensive ones may contain as little as 15%. Grain whisky and other fillers are usually much cheaper to produce than single malts, so blends containing them are usually much cheaper to buy. Most cocktails and mixed drinks that call for whisky use blended whisky. This is primarily for cost reasons, and secondarily because the complex flavours of single malt whiskies would be overshadowed by the mixer(s). Some examples of blended whiskies are Johnny Walker Red Label, Famous Grouse, Chivas Regal and J&B. Each manufacturer of blended whisky use persons called blenders to combine a number of different single malts and grain whiskies into their "brand style".
If the contents of a blended whisky is distilled and matured in Scotland, it is often called "scotch".

Age of whisky
The age statement on a bottle of single malt whisky is the age of the youngest malt in the mix, as commonly the whiskies of several years are mixed together in a vat to create a more consistent house style. On occasion the product of a single cask of whisky is bottled and released as a "Single Cask."
While "cask-strength", or undiluted, whisky (often having an alcohol content as high as 60%) has recently become popular, the vast majority of whisky is diluted to its bottling strength - between 40% and 46% Alcohol by volume (ABV) - and bottled for sale.
Note that "Single Cask" is not the same as "Cask Strength". The former indicate that it comes exclusively from one cask, but it can still be diluted to bottling strength, while the latter is undiluted but can come from different casks.
Unlike wine, whisky does not continue to mature in the bottle.

How whisky is made
Barley, yeast and water are the only ingredients required in the production of single malt whisky.
The barley used to make the whisky is "malted" by soaking the grain in water for between two and three days and then allowing it to germinate to convert starch to fermentable sugars. Traditionally in Scotland each distillery had its own malting floor where the germinating seeds were regularly turned. However, most of the distilleries now use commercial "maltsters" to prepare their malt.
The germination is halted (by heating) after 3-5 days, when the optimum amount of starch has been converted to fermentable sugars. The method for drying the germinated barley is by heating it with hot air produced by an oil, coal or even electric heat source. In most cases, some level of peat smoke is introduced to the kiln to add phenols, a smoky aroma and flavour to the whisky.

The malt is milled into a coarse flour (grist), and added to hot water to extract the sugars. The extraction is done in a large kettle (usually made of stainless steel) called a mash tun. At first, the hot water dissolves the sugars (maltose) and enzymes (diastase) in the grist. Then the enzymes act on the starch left over from the malting stage, continuing the conversion to sugar, and producing a sugary liquid called wort. Typically, each batch of grist is mashed three times or so to extract all the fermentable sugars.
Yeast is added to the wort in a large vessel (often tens of thousands of liters) called a washback. Washbacks are commonly made of Oregon Pine or stainless steel. The yeast feeds on the sugars and as a by-product produces both carbon dioxide and alcohol. This process is called fermentation and can take up to three days to complete. When complete, the liquid has an alcohol content of 5 to 7% by volume, and is now known as wash. Up until this point the process has been quite similar to the production of beer.

The wash is then pumped into a copper pot still, known as the wash still, to be distilled. The wash is heated, boiling off the alcohol, which has a lower boiling point than water; the vapour is collected in a condenser which has been submerged in cool water. The lower temperatures cause the vapour to condense back into a liquid form.
This spirit, known as low wine has an alcohol content of about 20 to 40%. The low wines are then pumped into a second pot still, known as the spirit still, and distilled a second, (and sometimes a third) time. The final spirit called "new make spirit" generally has an alcohol content of 60 to 70%.
The "new-make spirit", or unaged whisky, is then placed in oak casks to mature. By law, all Scotch whisky must be aged for a minimum of three years and one day in oak casks; though many single malts are matured for much longer. The whisky continues to develop and change as it spends time in the wood, and maturation periods of twenty years or more are not uncommon. Each year spent in the wood results in the evaporation of between 1 and 2% of each casks' contents, depending on the ambient conditions at which the casks are stored. Because alcohol is more volatile, the alcohol content of the remaining whisky drops over time. This is known as the angel's share.

Water or "on the rocks"?
A good way to totally kill a whisky is to serve it "on the rocks", i.e. over ice. The cold will kill the delicate flavors. You don't drink whisky to cool down when it is hot, you drink it to enjoy. Drinking it "on the rocks" just signals that you are a barbarian with no taste.
However, adding a few drops of water (distilled/bottled, at room temperature or just below) will release the flavors and also take the edge of the alcohol. However, not all single malt whiskies benefit from water. Some are perfect like they are, it is something I recommend that everyone test out themselves. I always start with a sip without any water added. I then add a few drops and try again. This gives me an idea, and I can either add a few more drops or stop.