Hovering over his two 37.5-pound bags of Washington-grown blackcurrants, Bardenay Distillery Manager Scott Probert looked like the proverbial kid on Christmas morning. His excitement was partly because the round, purple-black berries are rare in the U.S.—Probert explained that their production was banned in 1912 because they can carry blister rust, which threatened the logging industry—and partly because they're the continuation of his four-year dream to make cassis liqueur. Cassis is the French name for blackcurrant, and has become the near-universal way to refer to the alcoholic drink it produces because, as Business Insider reports, more than 99 percent of all currants now grow in Europe.
"Generally the U.S. citizen isn't familiar with blackcurrants," said Probert, adding that unlike their pink or golden cousins, blackcurrants "actually have some character to them. They almost taste like a Concord grape, but much more acidic."
After struggling to find a supplier, Probert eventually located a currant farmer in the Mount Baker region north of Seattle, Washington. Even then it wasn't smooth sailing: When he made the trip to collect them in July he ended up with a batch of golden currants instead, which are light and herbal instead of carrying bold and fruity flavors. Finally, in mid-August, a batch of ripened blackcurrants made its way to Boise, double-bagged in clear plastic, which Probert gleefully tore into at Bardenay's sunny Eagle distillery on a summer morning.
Behind him, production of the liqueur's other key component—high-proof alcohol—was already underway in the restaurant-distillery's new Vendome still, a beautiful copper and brass machine with a rounded belly and a standing column that looked just like an oversized flute.
"What would be the finger holes on the flute, each of these," Probert said, pointing to round porthole windows running the length of the column, "they're actually plates. The windows allow you to see the activity on each stage." During those stages, the liquid inside heats and cools, allowing the distiller to conduct separations. Droplets collecting on the glass windows tell Probert about the progress of the liquid, which is alcohol from a cane wine made from fermented cane sugar, yeast and water.
"We take that wine, strip the alcohol out using just the single stage of the still, and we end up with a crude alcohol. It's about 90 percent, but has a lot of character that we want to remove in later stages," he explained.
That alcohol soon began pouring from the still in a thin, steady stream, collecting in a large plastic bucket. Probert caught some in an empty wine glass, leaned in to sniff it and nodded his approval, wincing a bit.
"No matter how often you do it, it still blows you backward," he said. He wasn't kidding—even wafted with a hand, the fumes off the liquid were eye-watering.
Luckily, that dangerously high-proof alcohol wouldn't end up in anyone's glass. Probert explained that it had several more stages to go through in the still before it would be added to the blackcurrants, which he'd poured into a small metal tank and readied for blending.
"Each time we're extracting different chemicals, essentially, that we don't want," he said, pulling a heavy-duty immersion blender from a shelf nearby. "And that's where each of the stages comes in. That allows us to conduct the separations."
Eventually, the process yields about 50 gallons of usable-high proof alcohol, the equivalent of about 50 cases, or 600 bottles. But not all of that will go toward cassis liqueur.
"We've been making these in about five-gallon batches; five gallons will essentially yield two cases," Probert said, adding, "There's not a huge market for liqueurs." The size of the market keeps Bardenay's bottles out of liquor stores, but Probert said in-house demand for drinks mixed with cassis runs high. Soon, he'll have to run three cycles of the liqueur per month to keep up.
"We're stepping up our program. We've spent the last four years developing our liqueur program, and we started with a strawberry liqueur. Because strawberries are so delicate, trying to build a liqueur that really can stand up to alcohol is actually kind of difficult. So we figured if we can do it with that, then we'll start with other things," he said. "The end goal though was to do cassis."
Bardenay's line of liqueurs now includes not only cassis and strawberry, but banana and dark cherry as well. As Probert swirled the immersion blender around in the vat of berries, breaking their skins apart without fully liquifying them, he explained the final steps of the process: combining the high-proof alcohol with the blackcurrants and leaving it to macerate before pressing, filtration and bottling.
Though the batch he'd just worked on wouldn't be ready to drink for more than three months, Probert produced a finished bottle for tasting. It was thick and syrupy, very sweet with a dark, fruity character and a high punch of acid.
"A classic cocktail with cassis is the Arnot," Probert explained, pouring tastes of each liqueur into shot glasses. "That is essentially gin and cassis, and some Lillet Blanc. That one's really good, very fresh. The [other] classic cocktail is the Kir or the Kir Royale—the Kir is essentially cassis or another liqueur mixed in with white wine, and the Kir Royale is with champagne."
He added that the bar had just wrapped up the run of a special summer drink that combined cassis with fresh blackberry.
"I understand it was very popular," he said with a broad smile, "because we're almost out of cassis."