Walk into Oola, a small-batch distillery, and you’re greeted by what appears to be a copper sculpture of a giant stinkbug. Two spiral coils the size of hubcaps poke out of the top of a boxy, shiny frame. That’s Oola’s still, the result of an unusual fusion of art, utility, and chance. For a beautiful stinkbug, it produces quite a smell — and taste.
The Seattle liquor-making operation and many others like it popped up after a change to the state liquor laws in 2008 that opened the door to craft distilleries. The law let distillers sell their products directly to people; previously their wares could only be sold from state liquor stores, a difficult prospect for small-scale producers. Since then, voters have passed an initiative that shut down the state-run outlets, and liquor is now sold widely.
A friend brought me to Oola. Its gin — and I’m not at all a gin drinker — goes down smoothly with no sharp aftertaste. The latest varieties from Oola, including a citrus vodka and a rosemary vodka, are made with natural, primarily local ingredients, lending them subtle, fresh flavors.
But what really fascinated me at Oola was its still.
Oola’s still was crafted by a Seattle man known for making ugly, low-cost models. “My niche in the small commercial still-making business is that my equipment is about 10 percent the cost of the big names, but it’s not pretty,” says Mike McCaw, founder of the Amphora Society, which sells stills and books about distilling.
McCaw’s unadorned stills look like barrels of the kind you might imagine are used to store motor oil, with a couple of insulated pipes sticking vertically out the top. Copper coils may jut out here and there. He’s right when he says they aren’t pretty.
Oola’s owner, Kirby Kallas-Lewis, is an art dealer, and he kitted out McCaw’s plain design, installing copper cladding and the bug-eye coils to turn a workhorse into art. The result is a unique beast that Kallas-Lewis hopes will take him to the next level of distilling.
At the other end of the spectrum is 2 Bar Spirits, a newer Seattle distillery not too far from Oola. It makes no apology for the appearance of its McCaw-made still. McCaw sometimes advises distilleries to hang a sign saying that their stills don’t look pretty but are efficiently “green.” That’s because unlike the lovely hammered-copper spirits-making systems that are meant to be showpieces, his stills are typically surrounded with insulation that reduces the energy required to keep them at the correct temperature.
For a man whose stills are in bars and distilleries in South Africa, New Zealand, Australia, Ecuador, Mexico, Poland, Sweden, Great Britain, and Canada — and the U.S. — McCaw has been working at the craft for a surprisingly short period of time.
He was a research scientist at Weyerhaeuser for 20 years, working on process optimization for pulp and paper mills. “That’s about heat transfer and recovery to minimize energy use. These are exactly the same things involved in designing a good still,” he says. “A still is a heat engine. You put it in one end and take it out the other, and magical stuff happens in between.”
He’d long been a home beer brewer with “six different beers on tap at any one time,” but about 15 years ago he took an interest in distilling. While reading a book about making gin and vodka, he noticed some errors. McCaw wrote an email to the two authors complimenting the book but pointing out the problems. One of the authors didn’t take too kindly to his email, but the other was glad for the feedback. McCaw struck up a friendship with that author, Mike Nixon, who lives in New Zealand.
“Mike suggested we write a new, better book,” McCaw says. Over the next few years, the pair worked away, sending chapters back and forth via email. The result is The Compleat Distiller, first published in 2000 and now in its second edition.
Not long after the book was published, McCaw and Nixon started getting requests from readers who didn’t feel confident enough to build their own stills. “We originally considered ourselves publishers of this little book. But we got so many requests. This led to several visits to New Zealand, where we tried out ideas and came up with a hobby-scale small still,” McCaw says. They sold their first still around 2003.
A few years later, after new requests for commercial stills came in, McCaw designed the big brother to that small 2003 model; the new version could make a couple of hundred bottles of alcohol a day. The very first one, still in use, went to Fat Dog Spirits in Florida around 2006.
McCaw says the reason his stills are popular is that they’re cheaper and more flexible than the stills from the “big names” like Carl and Bavarian-Holstein. “All of these guys employ what I like to refer to as the finest 19th century technology,” McCaw says. “They’re building updated versions with modern instrumentation and modern steam hookups, but the fundamental operating principle is exactly the same as what was employed in the 1700s and 1800s.”
A distiller like Oola can start with a variety of ingredients but ultimately must have sugar and yeast. Heating wheat, oats, or barley with water, for instance, ultimately converts the starch in the grains to sugar in a process called mashing. The distiller then adds yeast, which converts the sugar into alcohol, resulting in a wash. The wash is then boiled in a pot still. McCaw’s pot stills look like a barrel with a wide copper pipe rising out, topped with a rectangular copper box and a drainpipe.
Mixtures of water and alcohol boil at different temperatures depending on the alcohol content: the higher the alcohol content, the lower the boiling temperature. As the liquid in the barrel heats, it gives off vapors that are stronger in alcohol content than the liquid in the pot. The vapors rise up the pipe into the rectangular box – called a condenser — where they become a liquid again in a process much like steam forming water droplets on a cold window. The liquid then runs out of the condenser through the drainpipe, where the distiller collects it in another barrel.
The resulting liquid, known as low wine, has a higher alcohol content by volume than the original product since much of the water has been left behind, but it’s still only about 40 percent alcohol.
Now the distiller passes that low wine through McCaw’s compound still. It’s heated again in a barrel, but this time the vapors travel up a column sans condenser. The column is filled with what’s known as structured packing, a material that fills the column and adds surface area. The idea is to increase the area onto which vapors can condense, allowing for a much shorter column than would otherwise be needed to allow for the condensation to occur.
McCaw designed his own structured packing, made of copper mesh, to offer 1,000 square feet of area over a cubic foot of volume. Most commercial still makers purpose-build stills for each kind of alcoholic beverage. Those stills commonly use packing called bubble plates, first invented in the 1800s, which can handle huge volumes of product but are less efficient than structured packing and are typically configured in a way that produces a specific product, according to McCaw.
Substances like acetone and methanol – volatile and foul-tasting byproducts that may occur, depending on the make-up of the wash – boil at the lowest temperatures. The distiller has to watch the temperature of the vapor at the top of the column. As the vapors of the unwanted alcohols collect at the top of the column and begin to condense, the distiller turns a valve to drain off the liquid; it’s then disposed of.
When the vapors begin to reach higher temperatures, indicating that they contain more desirable alcohols, the distiller lets the liquid fall back down the column, where it is reheated by the hotter rising vapors. The process redistills the liquid, further removing water and upping the alcohol by volume.
There are also heavier alcohols with higher boiling temperatures, and substances known as fusel oils that come at the end of the run. With McCaw’s compound still, the distiller can keep pushing them back down the column to get the greatest amount of good, clean spirits.
McCaw says his stills are unique in that they let distillers control and measure the vapor’s temperature in order to decide whether — and how quickly — to drain it off. That ability allows a distiller to make different kinds of alcohol in the stills, including vodka, gin, and whiskey.
“Here’s where the art comes in,” McCaw says. “It’s up to a guy like Kirby to try it with their recipe and determine what the temperatures are that give them the properties they want on their product.”
McCaw sells stills to as many as 12 commercial distilleries a year, in addition to many more to individuals. A commercial sale might include a handful of smaller stills, including a mix of pot and compound stills.
“He’d sell more if he made them prettier,” quips Oola’s Kallas-Lewis. He’s currently using seven smaller McCaw stills, plus the big copper-clad one. He hasn’t gotten the big one up and running yet but is pumping out around 150 gallons of product each day, including whiskey, which he enjoys making the most.
McCaw is not at Weyerhaeuser any more. “I retired four years ago when my little weekend business outgrew evenings and weekends,” he says. But he may not be at it for much longer. He’s nearly at the age when he can draw from his IRA. “My goal was to work less time than I did as a wage slave for a big company, have some fun, and replace my salary or do a bit better.”
He doesn’t do any advertising; customers come to him through word of mouth. He’s good with the volume of work he has. “With my niche right now on the commercial side, the typical customer is a guy with a lot of passion and not a whole lot of capital,” he says. “Those are fun people to work with.”
Photos by James Rooney.1
Nancy Gohring’s work has appeared in Wired, the New York Times, the Economist Babbage blog, MIT Technology Review, Computerworld, CITEworld, ITworld, and many other publications. She started writing about cell phones when they were huge and expensive, and now covers a wide range of technology and science topics.