PX SHERRY CASK
PX sherry is a wine created from grapes of the same name. The PX stands for Pedro Ximenez and describes naturally very sweet dessert wines. Here's more about PX Sherry and how it comes into play and affects a PX sherry cask finish bourbon...
Simply put, PX sherry cask finish bourbon is distilled and aged according to the legal requirements for making bourbon and then finished in a PX sherry cask for an additional amount of time. The finishing time can vary, but about six months seems relatively common.
What Is PX Sherry in PX Sherry Cask Finish Bourbon?
PX, or Pedro Ximenez, refers to the grapes used to make PX sherry, not to the name of a patriarch of a wine-making family or a name at all. However, one could assume that the name references an individual that had something to do with naming or developing these grapes. For a wine to legally be a PX sherry, it must consist of a minimum of 85% Pedro Ximenez grapes. In this way, it's similar to bourbon, since bourbon must be 51% corn to be considered bourbon legally, and some may label it "PX sherry cask finish bourbon."
When harvesting Pedro Ximenez grapes, they're usually picked when most other wineries consider them too ripe to use in the wine-making process. Sun drying is another process used in addition to or instead of harvesting them over-ripe. When picking over-ripe grapes or drying them in the sun, the sugars in the grape become more concentrated, producing a more affluent and sweeter grape. These grapes, more colloquially known as PX, are extremely sweet, more so when using a sun-drying process called asoleo.
What Is the PX Grape Asoleo Drying Process?
Asoleo or soleo, from sol which means sun, refers to the process of sun-drying grapes prior to pressing them into wine. The process is similar to making raisins or other sun-dried grapes. In addition to PX Grapes, asoleo is also used on Moscatel grapes. This process typically takes anywhere from one to three weeks, depending on several factors, such as the grape harvest that year, environmental conditions, the desired end finish, and the type of wine to be eventually made.
This process is not easy. It is definitely a labor of love ensconced in history. The grapes are spread out carefully by hand on straw mats, or redores, which are round straw mats in a dry, open-air environment. Once per day, all the grapes are turned over by hand, and if any grapes are or have gone bad, they will be removed from the batch. Also, the turning process serves to help keep pests away and maintain a consistent drying process. Once the grapes are dried to the desired level, they're ready to be processed.
Most of the PX sherry grapes come from a DO wine zone in Andalucia in southern Spain, called the Montilla-Moriles area. As the name implies, the Montilla-Moriles region is the area around the towns of Montilla and Moriles. For reference, this region is about 25 miles south of Cordoba and about 60 miles north of the Mediterranean coast at Malaga. The Montilla-Moriles area is the furthest north of all of Andalucia's DO wine regions. Here, the dry climate of the mountains reduces the issues that can occur and destroy the crop while drying.
How Do You Press PX Sherry Grapes?
Due to the fact they have less juice due to the drying process, pressing PX sherry grapes is a far more difficult task than it is with fresh grapes. PX sherry grapes are pressed in vertical presses in which the grapes are placed in layers with straw mats between each layer of dried grapes. Since the PX sherry grapes have an extremely high sugar concentration, they don't spontaneously ferment as traditional grapes do. Once the PX grapes begin to ferment, the PX sherry wine will naturally stabilize at about 20 proof and sit for many months before being fortified.
What Is PX Sherry Finish Bourbon?
Finishing whiskey in used PX sherry casks is not a new phenomenon. However, finishing true, legal Kentucky Straight Bourbon whiskey in PX sherry casks is a process that has only been done and perfected by a very small percentage of the bourbon-making industry. A complex example that pays astute attention to every detail involves using #4 charred new oak barrels to age high-quality raw distillate before moving to PX sherry casks for six months to finish the bourbon.
One of the upsides of a true, legal bourbon is that there are no additives in it, not even passive ones such as those from a used sherry cask. So, is this still bourbon? The answer to that, surprisingly perhaps, is yes, it is still bourbon. All legal requirements required to be called bourbon have been met. Once they've been met, you can legally add flavors (rarely if ever done), use any established finishing process, or experiment with your own to create something unique.
Therefore, PX sherry finished bourbon is legal bourbon. The PX sherry finished bourbons tend to have a much more in-depth flavor and aroma profile than the traditional, straight bourbon whiskeys. The sherry soaked into the wood of the cask imparts a myriad of new flavors, like bittersweet chocolate, toasted nuts, warm spices, and dried fruit. Herein you find the deep beauty and underlying enigma of bourbon, America's native spirit.
Distilling bourbon is an art form that involves the field in which the grain is grown, the grain itself, the distilling process, mash bill makeup, and the aging process. With straight bourbon, while still an art form, there are far more similarities than differences among the various bourbons produced. Utilizing the different finishing processes, such as PX sherry finishing, allows the creative mind to flow more and create an even more complex expression of our beloved bourbon.
If you're interested in learning more about the history of Kentucky bourbon, the distilling process, or how best to enjoy a glass of bourbon, check out the Rabbit Hole Distillery blog and website. You can also book a tour of our distillery, which is open to the public by booking reservation only.