If you were a somewhat rebellious teenager and happened to replace some of your parents’ vodka with water from time to time, you may have discovered that alcohol and water freeze at different temperatures. Alternatively, if you were a late-19th-century German brewmaster, you might have observed this phenomenon and seen opportunity. Enter the eisbock, the big, bold, booze-adjacent beer that is almost unheard of in American breweries.
What is an eisbock?
Simply put, an eisbock (pronounced ice-bock, which is its literal translation) is a doppelbock that has been freeze-distilled. To make it, the already strong, sweet, and malty German lager is chilled to subfreezing temperatures, at which point ice crystals begin to form in the beer. The ice crystals are then strained out, leaving behind a product that’s the opposite of watered down.
In and of themselves, freeze-distilled beers are not all that uncommon. It’s where the “ice” in Icehouse, Bud Ice, and Natty Ice comes from. The important distinction here is which kind of beer is being frozen and the amount of ice removed. The aforementioned beers begin with a light lager, and are iced up to a strength of about 5.5 to 6 percent ABV. But what if the base beer was stronger (hello, doppelbock) and further concentrated by the removal of much more ice? These are the makings of an eisbock.
What does an eisbock taste like? Well, like a doppelbock, but… more. A doppelbock is a strong, malty, and sweet German lager that usually ranges from 6.5 to 9 percent ABV. A decadent spin on regular bocks, the doppelbock is a much older style compared to the eisbock, and can be traced back to the late 18th century. While these beers are often referred to as “liquid bread,” that nickname undersells the sweet notes of toffee and hints of dried fruit present in a good doppelbock. Popular examples of the style include Pauliner Salvator and Ayinger Celebrator.
So, when a doppelbock is freeze-distilled into an eisbock, what’s left behind is an amplified version of it. The malt sweetness is more concentrated without becoming cloying. The notes of dark fruit burst forward with a port-like intensity. The toffee-raisin aroma is even more pronounced. Most astoundingly, despite the substantially higher alcohol content, the extra concentration of ethanol can be barely perceptible.
The history of eisbocks
The origins of the eisbock style vary depending on which beer bottle you’re reading the back label of. The most romanticized version of the story involves a negligent brewer’s apprentice leaving a barrel of doppelbock outside on the night of a deep freeze. The next day, assuming the beer was ruined, the furious brewmaster made the apprentice drink from the frozen barrel as punishment. To their surprise, the apprentice was delighted by the result of his happy accident. An alternative version of the myth involves a doppelbock freezing during transportation with similar effects.
Details aside, we do know for sure that the eisbock as we now know it can be traced back to Franconia in the late 19th century. Kulmbacher Brewery is widely regarded as the first to produce it commercially, and still sell it today as Kulmbacher Eisbock. While still relatively uncommon, a number of German breweries have since developed a take on the style. However, in the U.S., hardly any have been produced.
Why are eisbocks rare in the U.S.?
Usually, the scarcity of a given style comes down to it being overlooked in favor of hazy IPAs, fruited sours, and candy-laden stouts. While that may play a part of it, there’s another complicating factor preventing American breweries from being able to make eisbocks.
The main obstacle that prevents U.S. breweries from producing eisbocks can be found in the name of the method used to create them: freeze-distillation. While eisbocks fall well short of the proof of most spirits, the freeze-distillation method is still considered a form of distillation by the Alcohol and Tobacco Tax and Trade Bureau (TTB). As a result, any brewery that wants to freeze-distill its beer must also have a distilling license. Even for the small number of American breweries that meet this criteria, they’d also need a freezer capable of bringing the temperature of an entire batch well below 30 degrees Fahrenheit for a sustained period of time.
The only American brewery that appears to release an eisbock annually would be Kuhnhenn Brewing Company out of Warren, Mich.
Even home brewing an eisbock is considered illegal, as the TTB states only up to 0.5 percent of a beer’s volume can be removed via freeze-distilling to boost alcohol content, whereas a proper eisbock should have 20 percent or as much as 40 percent of its total water volume filtered out.
Breweries outside the U.S. have managed to push the freeze-distillation method to the extreme. For instance, in 2020, BrewDog and Schorschbrau collaborated to create the 57.8 percent-ABV Strength in Numbers. To reach that concentration, they utilized medical-grade freezers, and the beer was packaged in 40-milliliter bottles. Although “Eisbock” was on the label, that’s a bit of a misnomer, as a higher-ABV Belgian strong golden ale was used as the base beer.
Where can you find eisbocks?
While the production of eisbocks is regulated as though they’re a spirit, they’re fortunately treated like any other beer when it comes to imports, distribution, and sales. As a result, most available eisbocks tend to be imported from Germany and other European nations, though some American breweries have ventured to give the style a try. As mentioned earlier, the first eisbock produced was the 9.2-percent ABV Kulmbacher Eisbock. Though rare, it can be found in the U.S., both in bottles and occasionally on draft. However, the most readily available eisbock would be Schneider Weisse’s 12-percent ABV Aventinus Eisbock. In addition to being more widely available (though still uncommon), Schneider Weisse’s take on the style also provides the unique opportunity to do a side-by-side taste test with its non-frozen equivalent, Aventinus.
When it comes to American-brewed eisbocks, all we can say is good luck finding them. A select few breweries also carry distilling licenses, allowing them to legally freeze-distill their beers, but the end result is usually a small-batch taproom exclusive, and they’re historically brewed as one-offs. The only American brewery that appears to release an eisbock annually would be Kuhnhenn Brewing Company out of Warren, Mich. Not only does it release an eisbock, but raspberry and blackberry iterations as well. A few larger breweries have taken a stab at them in years past, such as Heavy Seas’ 2018 release Schnee Boot, a bourbon-barrel-aged take on the style. The good news is that because of their high ABV and rich maltiness, even a vintage bottle of eisbock will still be packed with flavor.
If you’re lucky, maybe your local brewery will hire a negligent apprentice next winter. Otherwise, all you can do is keep an eye out. In the meantime, we suggest seeking out other bold German styles instead. They’ll rarely let you down, and you may end up stumbling across a true eisbock.
The article The Cult of Eisbock (and Why Most American Breweries Will Never Be Able to Make It) appeared first on VinePair.