Fraley, who is 45 and has short black hair flecked with gray, projects a sort of crowlike intensity, and moves in bursts with little wasted motion. Her nose, alas, appears unexceptional, neither a button nor a beak. At the Ironroot warehouse, the plan for the day was to analyze the organoleptics of a variety of whiskeys that had been aging for several months. “Nancy calls it checking barrel health,” Jonathan said. “I call it a good Saturday morning.”

The number of things that can influence the aroma and taste of a spirit is astounding. Some aromas are created during fermentation, others develop when the fermented wash is run though a still, and a great many others emerge during barrel aging, as volatile elements and other compounds decompose and recombine with ingredients introduced by the oak. In whiskey, for instance, Fraley has identified hundreds of aromatic elements, ranging from the ethyl butyrate formed during fermentation, which creates a faint pineapple scent, to the unappealing boiled-vegetable smell from fusel oils that can creep in during inattentive distillation.

Fraley doesn’t believe that she has olfactory superpowers, but instead suspects that her brain is simply wired differently from most people’s, enabling her to separate, identify, and remember individual scents. She told me that whenever she comes upon a new aroma, it marks itself indelibly in her mind: the day and time she encountered it, the exact location, even the prevailing weather.

“It’s not always a blessing,” she said. “I just can’t get away from aroma.” Among the more aromatically memorable places she’s visited is Morocco. “I remember walking through the souks of Fez, and in one breath I might inhale spices from a spice vendor, and in the next moment a goat’s head festering in the sun with flies around it.”

New craft distillers are fast discovering just how many things can go wrong during the long trip from concept to container. Many of the errors Fraley diagnoses are common, such as poorly tended equipment, overly high fermentation temperatures, and bacterial contamination. Other issues are unique: At one distillery, she detected a touch of swimming-pool aroma, and found that the tanks were being improperly rinsed after chlorine washes. At another distillery, a staff break room was located amid the barrels, and the scent of microwaved curry had migrated into the spirits.

“There are just way too many people out there who see the romance in this but have no realistic conception about this business,” Fraley told me. “They buy these fancy stills with all the bells and whistles, but they can’t operate them.” So they contact Fraley in the way a homeowner might call an electrician after rewiring a wall sconce only to find that the nearby toaster outlet has stopped working.

On an encouraging note, she’s noticed over the past couple of years that though she’s still getting calls to fix problems, she’s getting more calls from new distillers asking for advice in advance, having heard the stories of disaster and heartbreak. The Likarish brothers fall in the latter category. The brothers met Fraley at a distilling workshop when they were hammering out a business plan. “We realized, Oh, we may be a little out of our league here,” Robert told me. “Within 15 minutes of talking to Nancy, I thought, She’s the one who can tell us if we’re doing something wrong.”