The Mos Eisley Cantina in Star Wars may not have been so far off with its intergalactic cocktails, because space is bubbling over with alcohol.
Ethanol molecules floating in gases within the interstellar medium (spaces between stars) essentially make space one immense brewery. As the universe cooled and expanded after the Big Bang, protons came into being as nuclear reactions occurred in the fiery and extremely dense cores of stars. These would be the nuclei of every atom that ever existed, including carbon, hydrogen, and oxygen, which are ubiquitous in star formation and throughout the universe. The chemical symbol for ethanol is C₂H₆O—meaning, with such an overflow of those elements, booze is always on tap.
The atmosphere of these astral distilleries is hardly as exciting as your favorite bar. While we tend to get mesmerized by the parts of nebulae washed in mystical reds and blues and greens, the UV radiation produced by emerging stars in those colorful clouds will obliterate most molecules. It is in the shadowy areas of the interstellar medium where the magic happens. Think of them as the sketchy dives of the universe. Gas in these spaces is as widespread as it is dense, and at -436 degrees Fahrenheit, much colder than a beer that’s been chilling in ice.
Because the gas in these dark interstellar dive bars is so cold and sluggish, atoms rarely come into contact, but those that do are far more likely to stick together and form molecules than those in the hotter hangouts, which are aggravated so much by the heat that they are constantly getting into atomic bar fights and crashing into each other before molecules can happen. When molecules do form in the dives of space, they will eventually stick to other molecules so long as they stay away from killer UV rays.
So how do you make a galactic homebrew? It takes much longer than anything you might ferment in your basement. The nine atoms needed for just one ethanol molecule take an agonizingly long time to interact, though such chemical reactions are expedited when these wandering atoms stick to grains of space dust. The bright lights of a nebula might be alluring, but this is why the coolest and dustiest dives in space are where you’ll find the most alcohol.
Before you rocket through the atmosphere with a beer mug in hand, it isn’t exactly happy hour out there. No breweries on Earth are going to cash in on some sort of Interstellar IPA anytime soon. Booze might be everywhere in the universe, but considering how vast it is, just one out of every 10 million molecules being ethanol qualifies as an overpour. You’d have to travel half a million light-years just to get a pint.
Better off hitting up even the most crowded bar in the city on a Friday night if you want a Guinness at warp speed.