Tmavé Pivo translates directly to "dark beer" from Czech, and that's what this is - a Czech-style dark beer. Lager, to be more specific. Produced in much the same way as the more famous Czech-style Pilsner, Tmavé Pivo tends to be richer and more malty than its German cousin the Schwarzbier, but it still hangs on to the enviable drinkability that all Czech beers demonstrate.
5% ABV