"Eisbock, a Frozen Curiosity
It is true that the modern “ice beer” was introduced by the Canadian brewery Labatt’s in the late 20th century, but the practice of concentrating a brew through freezing is definitely much older. It has been practiced in Bavaria for centuries, though nobody is sure exactly for how long. There is a persistent legend, which no one had been able to verify, which says that the first ice beer was made from a batch of Bockbier in the northern Bavarian city of Kulmbach, and that it was made purely by accident.

Apparently, a brewery lad — after a long day of toil in front of the mash tun — was too tired in the evening to roll the barrels of finished Bockbier from the brewery yard back into the cellar, as he had been told to by the brewmaster. He figured that there would be no harm in leaving them outside until morning. The night however, turned out to be bitter cold, and the beer inside the barrels froze solid. By the time the brew crew returned the following morning, the staves of the barrels had burst open. It appeared to all that the entire lot of wonderful Bockbier had been ruined. As the brewers inspected the frozen brew more closely, they discovered that, at the very center of each barrel, a small pool of murky, brownish liquid had collected. The brewers were unaware that alcohol has a much lower freezing point than water, and that it became concentrated as the beer froze from the outside in. As the water froze, the alcohol also transported with it all the essence of the Bockbier’s malty flavor to the center.

The irate brewmaster, bent on meting out severe punishment, ordered the hapless lad to crack open the icy barrels and drink the awful brownish stuff. The lad did as he was told, at first taking mere tentative sips, but then imbibing with ever increasing gusto. In the center of each barrel-size lump of ice was the most delicious, malty-sweet, and heavy beer imaginable. Punishment, indeed! The lad, of course, let the others partake in his “punishment,” too.

Thus was born, allegedly, the Eisbock, a Bockbier beyond even the realm of the Doppelbock. Still today, an Eisbock is made according to the principles that operated on that bitter cold wintry night in Kulmbach: A very strong Bockbier is partially frozen and then strained to eliminate much of the water from the brew. The result is a beer of almost 25% extract (which is about twice as much as for a “regular” beer). Most Eisbocks nowadays have an alcohol by volume level of 8 to 9%, but the mystique of the Eisbock is probably uniquely exemplified by the EKU 28 Kulminator Urtyp Hell, brewed in the Kulmbach of legend, to an alcohol by volume of approximately 13.5%."