Chemistry of Whiskey Flavor

Photo (L-R): Lorain County Community College students Clayton Mastorovich and Valerie Gardner. Senior Analytical Chemist, Envantage, Inc., Coleen McFarland. Lorain County Community College Professor of Chemistry Regan Silvestri. Lorain County Community College students Christopher Wright and Katie Nowlin.  (Photo by Ronald Jantz.)

Photo (L-R): Lorain County Community College students Clayton Mastorovich and Valerie Gardner. Senior Analytical Chemist, Envantage, Inc., Coleen McFarland. Lorain County Community College Professor of Chemistry Regan Silvestri. Lorain County Community College students Christopher Wright and Katie Nowlin.
(Photo by Ronald Jantz.)

At Lorain County Community College in Elyria, Ohio, chemistry students are using gas chromatography-mass spectroscopy to identify and profile the flavor compounds in whiskey.

Bourbon whiskey is made by a process where a grain mash is fermented and distilled into a clear spirit. (Remember from Organic Chemistry lab: distillation purifies a mixture into its components on the basis of differences in boiling point.) Traditionally, the clear spirit is then aged in new charred oak barrels for up to 10 years or more and is flavored with compounds that leach into the spirit from the charred oak barrel.

Here in our hometown, a company named Cleveland Whiskey discovered a way to dramatically speed up the aging process of whiskey.

While serving in the Navy, the founder and CEO of Cleveland Whiskey, Tom Lix, first learned how to distill alcohol from a chief petty officer who was making hooch from Kool-Aid on board a Navy ship. (The chief petty officer purportedly tapped into the ship’s heating system line to run the reflux and tapped into the ship’s cooling system line to run the condenser—but that’s just hearsay.) Now, 40 years and a doctorate in business later, Lix has developed an innovative technology that accelerates the aging process of whiskey from a few years to a few days. This process allows Cleveland Whiskey to abandon the soon-to-be antiquated practice of holding inventory for up to a decade while the whiskey matures. Lix calls his patent-pending technology “pressure aging,” and although the specific details of the process are proprietary, the procedure basically involves placing the new spirit in a stainless steel vessel with pieces of charred wood of a very controlled surface area. The stainless steel vessel is then sealed, and the head space above the liquid is subjected to a precisely defined cycling in pressure that forces the alcohol into the wood, extracting compounds from the wood that naturally flavor the whiskey.

Because Cleveland Whiskey was founded on the basis of a new technology for manufacturing whiskey, it’s essentially a technology company. Thus, as CEO of a tech company, Lix eagerly embraced the idea of establishing a cooperative research project using gas chromatography-mass spectroscopy (GC-MS) to identify and quantify the flavor compounds present in varieties of Cleveland Whiskey alongside traditionally aged whiskey. So where are we on the project now?

IMG_5846 2Traditionally, oak barrels have been used for aging whiskey because oak is a hard, durable wood that enables the barrel to maintain its integrity over the long aging period, thus preventing the volatile product from evaporating. Thanks to the technology that Tom Lix has developed, Cleveland Whiskey is not confined to aging with oak wood. Therefore, Cleveland Whiskey has used other varieties of wood to generate new experimental flavors of whiskey that are completely original, unprecedented, and only made possible via the innovative technology of accelerated pressure aging. Some of these unprecedented bourbon whiskey flavors include cherry, apple, hickory, maple, and honey locust, to name a few. In our chemistry lab at Lorain County Community College, we have samples of experimental whiskey flavors that are not yet commercially available!

We are using GC-MS to identify and profile the distinct flavor compounds that are leached from the various woods in these uniquely flavored bourbon whiskies. For example, we have seen that cherry bourbon, as compared with traditional oak flavored bourbon, has more ethyl octanoate, a compound known to impart a sweet fruity flavor. Further, we have seen that cherry bourbon has less phenethyl alcohol than traditional oak bourbon, which is a compound known to impart a floral and bready flavor. Currently, we are working to decipher the unique flavors in apple, hickory, maple, and honey locust aged bourbons.

Students currently working on the project include Katie Nowlin, Valerie Gardner, Clayton Mastorovich, and Christopher Wright. The inaugural students on the project were Aubrie Thompson and Chris Kazee. To all of these students, I (and whiskey drinkers everywhere) am greatly indebted for their dedication to enhancing the flavor of whiskey. We are grateful for the support of our research, which is provided by a Collaborative Opportunities Grant award from the American Chemical Society. And thanks to the ACS Two-Year College Faculty/Student Travel Grant program, our student Christopher Wright will present his work on the project at the Fall 2016 ACS National Meeting in Philadelphia.

Cheers! Salute! Za vashe zdarovye! (Or however you wish to say it.)

-Regan Silvestri, PhD
Professor of Chemistry, Lorain County Community College, Elyria, Ohio

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