As you might have seen, this week we published a write-up of my trip to Kentucky for a tour of Maker’s Mark and a preview of Marriott’s bourbon program. The trip raised a question, about bourbon, and Pappy Van Winkle, and Scotch, and the answer didn’t really fit into a piece already overstuffed with #WHISKEYFACTS!™
Basically, one major difference between bourbon and scotch is that to be called “bourbon,” the whiskey must be aged in new barrels. This isn’t a requirement for scotch, which is why you can buy “Caribbean cask” scotch aged in rum barrels (I had some Caribbean cask Balvenie 14 the other day, it was delicious) or other types aged in sherry barrels, and plenty aged in other used barrels of a type the label doesn’t bother listing (including plenty the used to hold bourbon). It’s also why age statements tend to be more prominent on scotch bottles than on bourbon, and why older scotch seems somewhat more sought after than older bourbon.
Another reason is climate. Kentucky, where a lot of bourbon is produced, is hotter than Scotland, and has more temperature variation. You’ll hear various equivalencies bandied about, where one year of bourbon aging in Kentucky is supposedly equivalent to anywhere from 1.5 to five years of Scotland aging, but the point is that bourbon, like your mom, tends to take on wood faster.
Maker’s Mark highlighted this point by serving us deliberately “over-aged” bourbon that, rather than mellowing with age as you might expect, just kind of tasted like chewing on wood chips.
Which brings us to my question.
If bourbon is especially susceptible to over aging, why is Pappy Van Winkle, which includes a 23-year-old bourbon among its varieties, the most sought-after bourbon on the market (or more accurately, not on the market)?
For my answer, I went to Dave Sweet, the president of Whisky Live and senior vice president of Whisky magazine. Dave was on the same tour I was, and suffice it to say, the man knows his whiskey. He seemed to be on a first-name basis with most of the master distillers, and could compare production processes in each. I figured if anyone could answer this question for me, he could. Naturally, the answer was both complicated and informative.
UPROXX: You know the question, hit me with it.
SWEET: It’s not that Pappy’s is special and stands up to 23 years of aging. It’s a combination of the type of whiskey it is, and then nurturing it very carefully, putting it in, I would imagine, a much colder than normal place in the warehouse.
Now, what happens with Scotch is, first of all, Scotch is in a used barrel. So you don’t have as much wood effect. It’s got to age longer just to get that effect. All the tannins, a lot of the stuff has been already been sucked out of the wood by the bourbon. The cellulose is already broken down a certain amount, all the sugars in the oak, and the maple is virtually non-existent. You get that maple candy flavor in bourbon, you get very little maple flavors in Scotch, or far less. Then, it’s a combination of the temperature. It’s not the temperature fluctuations, it’s just that Scotland on average is much, much colder, and has colder winters. Once the barrels cool down, it takes longer to warm back up in spring.
The cold does two things: one, it slows down all the chemical processes entirely, so it takes longer to get the same wood effect. The other thing is that it causes more alcohol to evaporate per gallon of water. When the water evaporates, the whiskey evaporates with it. When it’s hot, you have a much higher water loss.