Whiskey Gets Older, Faster

At NOLA's Root Squared, bartender Max Messier is experimenting with a tool that, in mere minutes, "ages" spirits that would normally take years to create in a barrel. Roger Kamholz explains the technology and implications behind rapid-aging whiskey.

At Square Root, chef Phillip Lopez’s newest New Orleans restaurant, the chef’s table is the only table—16 bar seats that face an open kitchen. According to Lopez, Square Root is the city’s first restaurant to build such a setup, one that brings to mind intimate, ambitious dining spots like the three-Michelin-starred Chef’s Table at Brooklyn Fare. The food at Square Root, served as a $150 multi-course tasting, is high concept and experimental; since it opened in late April, the restaurant has plated “petrified” salad greens, crispy wafers made of fried chicken and oysters garnished with buttermilk-and-horseradish ice. “We pretty much do whatever we want to do,” says Lopez.

Root Squared, a cocktail lounge headed by bartender Max Messier, occupies the space’s second floor. Before arriving in New Orleans a few months ago, Messier spent more than six years working at New York City bars and restaurants, including No. 7 in Brooklyn. Messier also hosted pop-up cocktail hours in New York City homes as “Brooklyn Bar Chef,” and, for a summer, quietly maintained a speakeasy known as the Cocktail Front. When he joined Lopez’s team they encouraged him to be unconventional and creative. Messier took that direction to heart. One of the techniques he’s begun experimenting with involves creating—in mere minutes—”aged” spirits, which, under normal aging circumstances, would take years to create in a barrel.

To do that he’s using the Sonicprep, a device sold by the culinary-equipment company PolyScience—well known in modernist-leaning kitchens for geeky tools like rotary evaporators, a smoker gun and a line of sous vide machines. The Sonicprep uses ultrasonic sound waves to—among a growing list of applications—create amazingly stable emulsifications and rapid infusions. Vinaigrettes just won’t come together properly? For just under $5,000 the Sonicprep will sort it out.

Design-wise, the Sonicprep consists of a sound-insulated chamber with a door and a hole cut in the top, a wand-like “horn” that emits high-intensity sound waves and a control box and power source that connects the wand through a cord. According to David Pietranczyk, the Sonicprep’s wand can deliver pinpointed sound waves into a liquid at rates as high as 20,000 pulses per second. Pietranczyk—a chef working at PolyScience who’s tested the Sonicprep’s culinary applications—talked me through the phenomena at play. The device creates microscopic cavitation bubbles that disrupt and needle their way in between molecules, as well as “minute shockwaves that can rip apart solids.” Basically, the Sonicprep allows liquids to mingle with and pass through porous materials extremely effectively.

It’s the Sonicprep’s intensity that begs the question, what else is it doing to whiskey, or any liquid for that matter? Pietranczyk is less certain. PolyScience doesn’t have testing equipment sensitive enough to measure whether, say, the same ultrasonic pulses that are allowing barrel flavor to more expeditiously exit wood aren’t also, in the process, breaking down esters and other components of flavor present in the spirit.

Phillip Preston, the president of PolyScience, found an intriguing use for the technology. With apples grown on his property, Preston makes “aged” Calvados using a combination of the company’s rotary evaporator (essentially a low-temperature still) and the Sonicprep. After fermenting apple juice, he can both extract and age the spirit in a matter of minutes. Over in Lower Normandy, the capital of Calvados, the barrel aging process clocks in at no less than three years. To impart the flavor and color of barrel aging, Preston adds charred wood chips directly to a volume of neutral apple spirit, and the concoction is “sonicated” by the probe of the Sonicprep. Under the duress of the sound waves, the chips relinquish their woody goodness as quickly as Earl Grey gives it up to steaming water.

The team at Root Squared has used this model to experiment with rapidly aging Bulleit Bourbon, which they singled out for its “neutral” flavor profile. Leftover scraps from the bar’s furniture—custom-crafted from used Jim Beam barrels—have found their way into the Sonicprep. First, the wood is toasted over a stovetop flame to achieve allover char. After 15 minutes of sonication, Lopez says the bourbon tastes as if it was aged an additional five years in a barrel. “We tried it initially,” Messier added, “and it was really good.”

In some ways, what’s taking place in the machine in those brief moments relates to what happens, over many years, in a whiskey maker’s rickhouse. As seasons change and temperature and atmospheric conditions fluctuate, whiskey passes back and forth through the barrel’s staves, gradually picking up components of flavor, aroma and color. By opening up the network between cells in wood on a microscopic scale, the Sonicprep allows for closer, deeper, faster contact between the spirit and the compounds that make a bourbon taste so delicious.

As distilleries, particularly small upstart ones, have explored ways to accelerate the barrel aging process in order to bring their products to market in less time, many have turned to using smaller format barrels, which might hold as little as 10 gallons of spirit (a practice which has been criticized as corner-cutting). Other recent techniques include submerging charred wood spirals into unaged spirit. But none of those can really top the Sonicprep for its speedy—and rather violent—approach.

It’s the Sonicprep’s intensity that begs the question, what else is it doing to whiskey, or any liquid for that matter? Pietranczyk is less certain. PolyScience doesn’t have testing equipment sensitive enough to measure whether, say, the same ultrasonic pulses that are allowing barrel flavor to more expeditiously exit wood aren’t also, in the process, breaking down esters and other components of flavor present in the spirit. Lopez is quick to say that, in his experience, sonication adds age “without harming the whiskey.” Ultimately, that’s a matter of taste. Messier, for his part, is eager to evaluate the technique more systematically; he plans to sonicate new-make whiskeys (i.e., unaged whiskeys) in the presence of oak which has been carefully charred to distillery-recommended levels, and then compare those results to their “slow-aged” counterparts on the market.

Depending on the results of these and other experiments, Messier says he could foresee the Sonicprep figuring largely into the cocktail program at Root Squared. For one, the technique could turn out barrel-aged cocktails in a fraction of the time—sacrificing less alcohol to evaporation and maintaining ingredients, like vermouth, that are susceptible to oxidization. Likewise, Messier envisions a day soon when he’s serving up Manhattans made with 10-year-old whiskey that’s never seen the inside of a barrel. But more interesting still is not how Sonicprep might factor into a cocktail programs, but whether or not it will find its way into distilleries.