Old Nation Brewing Fenestrum is a Czech Dark Lager by style. Old Nation's Fenestrum (fi-nes-trum) Dark Czech Lager balances drinkability with a full body and aromatic complexity, embodying the essence of continental Lagers. Hints of dates, sweet bread, milk chocolate, and coffee subtly tantalize the palate. This craft beer is 5% ABV and 25 IBUs. In this craft beer review, we will take a look at the color, smell, and taste.