There are more than 300 casks of whiskey aging in the Spirit Works Distillery barrel house, each uniquely crafted — different mash, different age, different American white oak barrels.
But there are 12 reserved in a different section of the room, stacked against a wall to the left of the entrance to the cavernous hall. Six have headphones stretched across their rounded sides, blaring music from playlists selected by Spirit Works’ employees. The other six, the “control barrels,” sit adjacent to them in silence.
These barrels are part of what the distillery has dubbed its “Music Barrel Experiment.” The idea is to find out whether the musical vibrations’ agitation of the whiskey — moving the liquid in and out of the porous oak barrel staves deeper and more frequently, gathering flavor — would make a difference in the spirit after it’s harvested.
In June, the public got to sample the outcome for the first time, as Spirit Works harvested the first two barrels from its experiment: a “symphony barrel” exposed to “The Nutcracker Suite” for three years nonstop, and its “bluegrass barrel,” exposed to a bluegrass playlist compiled mostly of songs from Americana band, The Devil Makes Three. The Sebastopol distillery isn’t alone in its hunch.
Around the country, spirit producers are coming up with different ways to increase agitation of their whiskeys to speed up the maturation process, though that’s not what Spirit Works is angling for, necessarily.
Tuthilltown Spirits in upstate New York uses a similar process it calls “sonic maturation,” where subwoofers rattle the distillery’s whiskey warehouses. In Kentucky, Copper & Kings American Brandy Co. does the same, calling it sonic aging.
And James Oliverio, a composer and expert in sound, said Spirit Works’ owner Timo Marshall and the rest just might be on to something.
“I’m not saying that it’s bogus or anything at all,” said Oliverio, professor of music and digital arts and sciences at the University of Florida. “I mean, there’s no question that sound frequencies and acoustic wave forms can influence matter. ... I guess the question is, what are the right frequencies and the right intensities that would actually produce the desired effect?”
Mostly though, Marshall said, he was just curious.
“There are so many different aspects to maturation of whiskey, and they’re all pretty scientific in terms of how the liquid interacts with the wood,” Marshall, 45, said. “So that’s what I’m interested in is how the liquid interacts with the wood, because that’s where so much of the flavor of the whiskey comes from.
“And we’re interested in thinking about different ways of how we could excite that boundary, with the idea that there would be more activity, more extraction of flavor, more movement of the whiskey into the barrel (wood) and back out again.”
Some things to take into consideration about how different sounds might affect the liquid include frequency and amplitude of the sound waves, Oliverio said.
Symphonic music, like “The Nutcracker Suite,” has much more variety than bluegrass music, which, like most popular music, he said, tends to be more repetitive.
“Classical music has loud parts and soft parts and high instruments and low instruments and different combinations and different rhythms going on, so perhaps that variety compared with a relatively small difference in changes could account for a different action in the liquid,” Oliverio said.
For Spirit Works, Marshall said, “it’s serious, but it’s also tongue-in-cheek. We do have a sense of humor.”
The first sample of the experiment, available now in the Spirit Works Distillery tasting room, comes from four barrels of rye whiskey harvested and bottled in May, each aged for three years in the 53-gallon barrels.
During a blind tasting the distillery hosted for its club members a few weeks ago, the barrel that sat through “The Nutcracker” for three years won best-tasting. On the pour, that batch also was noticeably darker in color than the rest.
“It goes back to it being about that movement,” said Lauren Patz, head distiller. “There might be times when there are more vibrations with “The Nutcracker,” compared to Americana music.”
Batches not yet ready for harvest include barrels being exposed to bands like Daft Punk, Led Zeppelin, and a playlist of Michael Jackson and Prince songs, among others.
The idea came to Marshall in 2013, right after he and his wife, Ashby, first opened Spirit Works.
Thinking about agitation techniques, he decided to give the music vibrations idea a try. And when he thought of American whiskey, bluegrass immediately came to mind, he said.
“I bought some cheap speakers online, and I stuck them to the back of a barrel and started pumping music into it,” he said. “And then Ashby turned around, and she said, ‘Why are you saying that the whiskey loves bluegrass, or is going to work well with bluegrass? Maybe it would also work well with the ballet.’”
Attending “The Nutcracker” is an annual affair for the couple, and that’s how the second barrel got its playlist.
“It was just a one-barrel experiment to begin with, but that’s how things happen in a craft distillery,” Marshall said. “People like it, people respond so well to it. When you get members of the public coming here to taste in our tasting room, there’s something about it that feels real and down-to-earth and passionate.”
You can reach Staff Writer Christi Warren at 707-521-5205 or firstname.lastname@example.org. On Twitter @SeaWarren.