According to Michael Crowder, chair of the Department of Chemistry and Biochemistry at the University of Miami, a glass of bourbon contains about 10,000 distinct chemicals.
And unlocking the right chemical combination can make the difference between a $ 10 bottle of bourbon and a bottle that sells for $ 2,500 a bottle.
Crowder and his team closely study bourbons using analytical chemistry. Crowder, who is now also acting vice president of research and innovation in Miami, said the idea for the project originated several years ago, when faculty began offering a fermentation course. for seniors.
“At the end of the first fall semester, the successful students were invited to attend a four-day distiller’s workshop at Moonshine University in Louisville, Ky.,” Crowder said.
The workshop included lectures from experts in the field of distillation and lessons on making moonlight.
“It was really interesting to me how different all of these bourbons are,” Crowder said. “All bourbons use the same four ingredients, corn, malted barley, rye and wheat. Most use similar yeast and equipment, and yet their product is so different… you can tell by the taste.
Crowder said he wanted to use chemistry to tell the difference between bourbons. His goals were to find the chemicals they contained and their toxicity levels, as well as to authenticate high-end and low-end bourbons.
“Marketing is a big part of bourbon sales, and some sell for $ 2,500 a fifth and some sell for $ 10,” he said. “Unscrupulous people could get a $ 2,500 bottle, empty it, fill it with cheap bourbon, and then sell it at the original price. ”
In his research, Crowder used three different techniques. “The simplest is called nuclear magnetic resonance, or NMR,” he said. “If you’ve ever hurt yourself and needed an MRI, it’s the same technology,” Crowder said. “We take the bourbon and put it in a big magnetic field and shoot light on it, basically. Different parts of the chemical react differently depending on the chemical identification.
With NMR, the concentration of certain chemicals can be easily discovered. “We have discovered a chemical that gives bananas the flavor and smell,” Crowder said. “We can also detect that there are chemicals that taste like vanilla in bourbons, and we can detect it in very high concentrations.”
Thanks to the peaks in the recorded spectrum, Crowder said he could identify chemicals in a sample in just a few minutes. It also uses liquid chromatography with mass spectrometry and gas chromatography with spectrometry in its analysis, two methods for detecting and categorizing compounds more complex than detectable by NMR.
With these techniques, Crowder said, “When you smell a bourbon, we’re going to detect the chemicals your nose is actually interacting with. ”
For Crowder, one of the most interesting parts of his research was discovering that as bourbons age, the chemicals in the barrels are oxidized.
“Ethanol and water can make their way through wood and oxygen can come in,” he said. “All of the different chemicals that you taste and feel when you taste bourbon are actually due to chemical reactions.”
Some bourbons, Crowder said, are packaged bourbons. “There is a big market for them right now. Essentially, once a bourbon has aged, it is put into a used barrel where other spirits have lived, ”he explained.
Crowder said a Kentucky company, Angel’s Envy, ages their bourbon before letting it sit in barrels of port wine from Portugal. The additional conditioning further changes the chemical composition of the bourbon.
The more research is done, Crowder said, the more light is shed on the complexities of bourbon and the aging process.
“Do we understand all the chemistry? Crowd asked. “No, and I don’t think we’ll ever do it.”
Crowder said his project would continue, but added that so far his team had not received a federal grant. Instead, some federal sources have suggested he is looking to distilleries for research funding.
“I have mixed feelings about this because it’s hard to stay at a distance,” he said. “If one distillery funds our research and we find out that they have a much higher concentration of toxic chemicals in their bourbon than everyone else, we might have trouble publishing this.”
“We will continue to try to get funding for this,” he said, adding that the US Department of Agriculture, National Institutes of Health (NIH) and National Science Foundation (NSF) were all possible sources of support. .
Most of all, Crowder said he liked the more individual side of bourbon.
“I always say there’s a bourbon that when I taste it I smell my grandmother’s attic,” he said. “And it’s absolutely wrong for a bourbon steward to say, ‘You don’t smell your grandmother’s attic. “How would they know? A lot of bourbons have to do with how you experience and how you taste and feel.
Drinking bourbon is a very personal experience, Crowder says. “That’s what I think is really cool about this whole process,” he said. “And the great thing is that the chemistry confirms that people taste different things. It has to do with how they feel.