It's a familiar origin story: an astronaut journeys into space for a routine exploratory mission — but something alien is lurking in the vacuum nearby. This unknown force messes with his chemical makeup, and when our hero returns to Earth, he seems... different, somehow. It happened to the members of the Fantastic Four; it happened to Johnny Depp in The Astronaut's Wife; and now, it's happened to an even more beloved icon: whiskey.
This past week, four tasters at the Ardbeg Distillery in Islay, Scotland drank samples of whiskey that had aged for nearly three years aboard the International Space Station. They compared the samples to whiskey that had matured in a similar way here on Earth. The team said the space samples were completely unlike anything they had ever tasted before; something about the space environment had a distinct effect on the alcoholic beverage. "It was the most unusual tasting we’d ever done," Dr. Bill Lumsden, head of distilling and whiskey creation at the Glenmorangie Company, told The Verge. "I was amazed at how different the samples were."
The space samples were completely unlike anything they had ever tasted before
Lumsden hopes the test will help him learn more about the whiskey maturation process, but overall he prefers his whiskey aged on Earth. The space whiskey had a much smokier quality, with flavors akin to cherries, prunes, raisins, and cinnamon, he said. He also noted that the whiskey's aftertaste was "pungent, intense, and long, with hints of wood, antiseptic lozenges, and rubbery smoke." This was in contrast to the Earth-aged whiskey, which had richer flavors more characteristic of whiskey drinks. The space whiskey still had strong flavor, but they were strange, Lumsden said — and not particularly good. He still has yet to figure out why. "That I haven’t been able to work out yet," he said.
The journey to this cosmic taste test began in 2011, when the Ardbeg Distillery sent samples of its single malt scotch whiskey to the ISS aboard a Soyuz rocket. The experiment was a collaborative publicity stunt from the distillery and the Texas-based research company NanoRacks, which helps to coordinate commercial experiments in space. NASA policies prohibit pure commercial programs, so the companies got approval by proposing a study of how the absence of gravity might affect a class of organic compounds called terpenes. These are the compounds that give whiskey its flavor, as well as the flavors of some fruits and vegetables. Lumsden figured the experiment might reveal some unknown facets of how whiskey ages.
Maturation is the final leg of the beverage's production. First, whiskey is made from fermented grains — such as barley, rye, and wheat — which are then distilled through a copper still; this helps to separate out the alcohol from the grains. Then the resulting distillate is put inside an oak cask and left to mature for a few years. During that time, the whiskey interacts with the wood of the cask. The alcohol seeps into the wood and evaporates, while chemical compounds in the wood leech out into the spirit, creating the aromas and flavors characteristic of the drink.
"The spirit gets mellowed, and the alcohol level drops a bit. It extracts flavor from the oak, which makes it sweet and complex," said Lumsden. "The maturation in the barrel is the most important stage in making the whiskey. It would be quite rough and fiery otherwise."
"The maturation in the barrel is the most important stage in making the whiskey."
To perform this process in space, however, Lumsden had to downsize. There isn't a lot of room on the ISS, so he couldn't send up full oak barrels filled with whiskey. Instead, he sent up 32 small samples of distillate, along with wood shavings carved from inside an oak cask. The whiskey and wood shavings were packaged together in special tubes called MixStix. Inside the tubes, a glass barrier kept the distillate and the shavings separated. Then when the MixStix samples made it to the space station, the astronauts broke the tubes' internal glass barriers, allowing the wood and the distillate to mingle. Lumsden did the same for six MixStix samples back on Earth.
MixStix enable the mixing of fluids in microgravity. (NanoRacks)
Then they waited. The samples remained on the ISS for 971 days, before returning to Earth in September 2014. Lumsden said he decided to let the samples age even longer after the Ardbeg Distillery received the samples in November. "Because the volume was so small, I knew I’d get one shot at the tasting."
When the time was right Lumsden and three other tasters carefully extracted the samples. They studied the whiskey with three types of analytical methods: gas chromatography (GC) to study the drink's gas composition; high-pressure liquid chromatography (HPLC) to figure out the individual components of the mixture; and good old-fashioned drinking and smelling.
The chemical ratios inside the samples were wildly different
In most aspects, the space and Earth samples were fairly similar. They both had roughly the same alcohol levels, as well the same levels of gases and major volatile compounds. The two diverged greatly, however, when it came to the number of wood extractives in each sample. These are the elements from the wood that seep into the drink during maturation. The space samples had a much higher overall concentration of these compounds, but the Earth samples had higher levels of specific compounds known as lignin breakdown products — the major activators of flavor in whiskey. All in all, the chemical ratios inside the samples were wildly different.
Lumsden is still trying to figure out how exactly this happened. "It’s very difficult to prove, because it’s happening on such a small scale," said Lumsden. "But when the spirit soaks into the oak wood, microgravity has inhibited that process a bit." He thinks the space environment may also be messing with capillary action — the intermolecular attraction between the liquid and solid materials. Somehow, the drink and the wood are interacting much differently than they do here on Earth.
With this odd taste test over, Lumsden said he hopes the results will help whiskey makers better understand the process of maturation. "There are hundreds of different flavor compounds in whiskey, and we don’t understand where they all come from. This experiment won’t solve it, but it will add another piece to the jigsaw, helping us to find new flavors." He noted that the ratios of chemical compounds within the space whiskey could also be used as a "marker" for finding whiskey that hasn’t aged properly. So in other words, if your whiskey tastes like space whiskey, you did something wrong.