To make ice beer, one would typically start by brewing a strong lager or ale, and once the beer has undergone primary fermentation, it's subjected to a process known as freeze distillation. This entails freezing the beer and removing the ice that forms, which concentrates the alcohol and flavor in the remaining liquid. The process can be repeated multiple times to achieve the desired concentration. The resulting beer is known as an Eisbock in Germany, where this technique originated. The key aspect of making ice beer is the freeze distillation process which concentrates the beer's alcohol and flavor.