November 21, 2017
Chances are none of professor Dana Ferraris’ organic chemistry students had considered a career or internship in whiskey making before Miscellaneous Distillery owner Dan McNeill visited class.
But not five minutes into the Mount Airy, Md., distillery owner’s talk, their heads began to nod in understanding. They grinned as they realized that making rum, rye, vodka – spirits — is chemistry. Organic chemistry and, in fact, the distillation experiment they would moments later conduct.
“Any chance I get to incorporate real world applications into learning and lab, I’m going to do it,” said Ferraris. “Distillation is such a HUGE part of organic chemistry — just about every chemical/solvent/reagent that we use came from petroleum or crude oil.
“And how were they purified? Distillation.”
Eagerly admitting he would also have liked to have an oil refinery scientist visit class but didn’t know any, Ferraris made the most of McNeil’s expertise in whiskey making. The class learned about various distillation fractions in spirits — the impure heads and tails that come off before and after the hearts or ethanol that makes whiskey the alcoholic beverage it is and the unavoidable and crucial impurities in the hearts that give various spirits their flavors.
It all begins with grain, supplied to Miscellaneous Distillery entirely by Carroll County farms and milled locally at Union Mills Homestead, McNeill said. Each spirit, from rye to rum to vodka and bourbon, starts as a mash that ferments the available sugars to make an alcohol wash. The combination of ingredients helps determine the flavor and consequently the spirit that results.
“I pushed myself to learn the scientific techniques,” said McNeill, who majored in Philosophy at the University of Northern Colorado and co-owns the distillery with Meg MacWhirter. “Then I create the whiskey by taste testing based on my own palate. So you might say it takes someone being half scientist and half artist.”
Fermentation results in a dozen or more liquid ingredients or chemicals in addition to the targeted ethyl alcohol. A mixture of liquids with different boiling points can be separated through distillation. In distillation, the mixture is heated and as each ingredient reaches its boiling point, it vaporizes into a distillation tube where it condenses into a collection vessel in a purified form of that particular chemical or ingredient.
Most of the impurities or other chemicals come off at the beginning or end of the distillation process with the ethanol being the largest percentage at a mid-range boiling point. Flavor, however, depends not only on the initial recipe of grains and even the specific soils or regions they are grown in but also on what trace impurities are left in the ethanol.
Science gives way to art when a distiller begins to determine at what point to collect the distillate — surely during the mid-range of the temperature near the 173.1 degree boiling point of ethanol but also during transition from heads to hearts and hearts to tails so as to retain some of the impurities or flavors that lend hints of butterscotch, bread, spicy black pepper and more to the spirit being made.
With mostly under-21 sophomore and junior Biology, Chemistry and Kinesiology majors in the class, the goal of the day’s organic experiment was not to create bottle of rye or rum. Instead, Ferraris supplied his students with a 40 milliliter mixture of 90 percent ethanol and 10 percent methanol. Their goal? To purify the ethanol by getting rid of the nasty methanol through distillation.
“It’s one thing for the students to do a crappy distillation, get a poor yield and have a little methanol in some of their fractions,” said Ferraris, explaining that the students will analyze their results using gas chromatography, which will show the percentage of ethanol as well as the percentage of even trace amounts of methanol or other contaminants. “But it’s another thing entirely when Dan gets a poor yield on an industrial distillation and has to throw away several cases because it’s contaminated with some undesirable compounds.”
As the students put on their lab coats and safety goggles, Ferraris added one more incentive — as if learning the connection between organic chemistry and whiskey making weren’t enough.
“By the way,” he said. “The group that gets the highest yield of ethanol gets Starbucks gift cards.”
No one seemed to mind that coffee and tea not whiskey or rum was the prize.