As per the website of Michael Agnew, who is a certified "Cicerone":
"To make this beer they brewed a 10 percent ABV Imperial Stout and aged that in barrels for 18 months. This aged beer was then taken to an ice cream factory where it was frozen. The water content of beer freezes at a lower temperature than everything else, allowing them to run off a concentrated version of the original beer. After a couple of freeze/runoff cycles they ended up with Tactical Nuclear Penguin."
The stats of TNP run as follows: 32 percent alcohol-by-volume (versus the 27 percent of Utopias), and about $50 for an 11.2-ounce bottle for the first 250 bottles of the 500-bottle run. After that, the price jumps to about $400 a bottle, but includes shares of stock in the BrewDog company. (Utopias retails for $150 a 24-ounce bottle.)