Which style is produced by freezing a portion of the wort to concentrate sugars and raise alcohol?

• A. Eisbock
• B. Doppelbock
• C. Baltic Porter
• D. Weissbier

Answer: (A)

Freeze concentration is the technique behind this style: you partially freeze the beer and remove the ice that forms. Since water freezes first, the remaining liquid becomes richer in sugars and alcohol, so its alcohol level climbs and the malt character deepens. This approach is what gives Eisbock its signature strength and intense malt backbone, with a smooth, chewy mouthfeel and often dark, warming flavors.

Doppelbock is a strong, malt-forward lager built up through traditional brewing and extended conditioning, not through freezing; it doesn’t rely on ice removal to boost its strength. Baltic Porter is a dark, robust style from the Baltic region, notable for its roasted malt and sometimes higher alcohol, but it also isn’t produced via freeze concentration. Weissbier is a wheat beer, highlighting yeast-derived notes and a lighter, fruitier character, unrelated to any freezing process.

So the style produced by freezing a portion of the wort to concentrate sugars and raise alcohol is Eisbock.