Emily began by explaining the mashing process. It is pretty “old school”. For starters, the bourbon mashbill is a bit unconventional, consisting of 88% corn and 12% malted barley. No secondary grains, such as wheat or rye, are added. There are no large cookers here, either. The whole process takes place in 55 gallon drums. The grains and hot water are added, and the mash begins. When the time is right, backset (Southern Grace uses the sour mash process) and yeast are added, and those same drums serve as fermenters. This is a technique more common in the moonshining world, but it works just fine for bourbon as well. Fermentation generally takes about 8-9 days. The grains are locally sourced; the corn is from Barrier Farms, about 4 miles away, and the malted barley from the Carolina Malt House, in Cleveland, NC.
Next it was on to the stills, nicknamed collectively as "The Torn and Frayed”. Southern Grace has two pot stills, individually named Keith Richards and Fats Domino. Each is connected to two doublers. The average proof of the bourbon distillate is in the 140’s coming off the stills. The distillate then gets proofed down to 105 for barreling. As of October 2020, the bourbon is aged for two years prior to bottling. However, aging at Southern Grace isn’t just a bunch of barrels quietly tucked away. Oh, no. At Southern Grace, aging is a “blast”, quite literally. That’s because they employ a process called "Sonic Aging” to help mature their whiskey. There are a few distilleries practicing this method. Probably the most well know, but not necessarily the first, is the band Metallica with their Blackened Whiskey.
What is sonic aging? It is using sound to enhance or accelerate the maturation of whiskey or other spirit, wine or even beer. In a nutshell, the theory behind this process is that the vibrations (or pulsations, according to Copper & Kings, who also use this process to mature their brandies) induced by loudly playing music will cause the whiskey to have more interactions with the wood than if it was left in a quiet environment. This constant movement will theoretically result in the extraction of more barrel flavors and accelerate the whiskey maturation to some degree. Some believe that it is the bass notes that are most responsible, and distillers will create a curated sound track to elicit a specific response from the aging whiskey.
The sonic barrel aging takes place in the original cell blocks, East and West. Also within these cell blocks is a small tasting area where barrel picks, as well as “Barrel House Tastings" take place. After aging, bottling is done by hand. A four bottle filler is used to fill the bottles, labels are printed and attached by hand, and the bottles are sealed. The bourbon is bottled at barrel proof, which is close to 100 proof and lower than it began.
Our tour finished back in the visitor center with a spirit sampling. Southern Grace makes spirits other than bourbon, and we had the opportunity to taste many of them. We sampled Sun Dog 130, a 130 proof corn whiskey; Zero Dark 130, a 100 proof version of the Sun Dog; Sun Dog Pink Lemonade & Sun Dog Apple Dumplin', 45 proof corn whiskeys blended with fruit juice; and my favorite, Conviction, their bourbon. There are also some special releases, such as a Double Barreled Bourbon and some interesting forthcoming wine, sherry and cognac cask finished bourbons.
Whiskey Prison is a unique place to visit, and they are producing some tasty whiskey. Be sure to visit when you are in the Charlotte, NC area. The history and the whiskey making are worth the price of admission, and you certainly don’t want to miss the opportunity to drink behind bars!