Whisky Flavor – Not Just a Matter of Taste.

The chart above provides a quick look at the flavor spectrum of whisky in Scotland and Ireland. Many of the brands that you might recognize are scattered across a spectrum from Delicate to Smoky and from Light to Rich. If you’ve been following previous Whiskylove articles, you may remember that all whisky gets its flavor from ingredients, from distillation, and, most importantly, from the aging process. But how? Where do these specific flavors come from?

First of all, if we look at ingredients, we’re talking water and grain. Barley, the source of all single malt Scotch whisky, gives a roasted, toffee sort of taste. Corn, the primary grain in Bourbon and other American Whiskey, provides a vanilla and a sweet, syrupy flavor which comes across as a sort of leathery taste. (according to the experts). Rye, on the other hand, tends to make a whisky that is spicy and dry to the taste. And wheat offers a (wait for it) whole wheat bread kind of taste, which is probably why there aren’t many wheat based whiskies out there. As well, malted grain (germinated, dried, and ground) offers a different taste than unmalted grain, as does the level of smoke infused into the malting process. The water source speaks for itself, and many distilleries boast about their unique and special water supplies. So, when you pop open that favorite bottle of whisky, the distinctive taste originates with the ingredients. This is referred to, again, by the experts, as the terroir – the flavor that comes from the whisky’s origins that sticks with it throughout the entire process. This is your first clue for figuring out which whiskies you like and which you may not.

Let’s move on to distilling. When the yeast breaks down the grain to form alcohol, there are a bunch of naturally occurring oils and other compounds released into the mash. When distilled, these rise as the heat in the still rises. The goal, obviously, is to allow the alcohol to rise up the the still in order to be collected. But the oils and ethers and acetones and other flavor-holding-compounds rise as well. If the still is very tall, then only the lightest of these compounds reach the top. In a short still, however, many of the heavier oils make it through and get captured in the taste of the whisky. But, remember, no new tastes get introduced during distillation. It’s just a fine tuning of the flavors that were already there. Interestingly, one of the big factors in how distilling affects flavor is the skill of the still operator. Controlling the flow of whisky through the distilling process is a combination of art and science, and distillers train for decades to master their trade. Same is true of blending.

And now the big one – aging. It’s all about the barrel, or cask, or butt, or whatever else they choose to call it. Whisky barrels are always made of oak, which is usually charred prior to use, creating a thin layer of charcoal on the inside surface of the barrel. I’m not sure how this step was discovered in the whisky making process, but I suspect that it was, like most fires, a fortunate accident. The charring does a couple of things – it releases sugars in the wood, and it creates a charcoal-type filter to help get rid of off-flavors, known as congeners.
All bourbon must be aged in new, unused, charred, oak barrels. These barrels create a unique flavor along the lines of vanilla and caramel. Conversely, the frugal Scottish use any type of barrel that they can get their hands on – old bourbon, port, wine or sherry barrels, along with the occasional virgin oak barrel. Each of these offers its own unique set of flavors. Plus, many scotch whiskies are aged in more than one type of barrel. Further, because the frugal Scottish use these barrels several times, the flavor intensity diminishes each time it is used. So, if you like the taste of a sherry finished scotch, you’ll really like a first-fill whisky, which, of course, will cost a little more.
And then there is time spent in the barrel. And the environment around the barrel. Whisky ages more slowly in colder climates, for example, than in warmer areas. In very simple terms, there are natural chemicals in the whisky, such as phenols and esters, that bind, over time, to the molecules in the oak. The longer whisky is aged, the more molecule binding takes place and the smoother the taste becomes. It also gets stronger due to gradual evaporation of the whisky through the barrel walls. In the whisky business, this loss is called the “angel’s share”. Lucky angels.

If we look at all the possible combinations of ingredients, distillation methods, and aging options, we can see how wonderfully variable the results are. Now all we need to do is taste them and enjoy…

Next time, we’ll take a peek at the basic elements of a good whisky collection.