Complex, pleasantly sour/acidic, balanced, pale, wheat-based ale fermented by a variety of Belgian microbiota.
Gueuze is traditionally produced by mixing one, two, and three-year old lambic. "Young" lambic contains fermentable sugars while old lambic has the characteristic "wild" taste of the Senne River valley. A good gueuze is not the most pungent, but possesses a full and tantalizing bouquet, a sharp aroma, and a soft, velvety flavor. Lambic is served uncarbonated, while gueuze is served effervescent. IBUs are approximate since aged hops are used; Belgians use hops for anti-bacterial properties more than bittering in lambics. Products marked "oude" or "ville" are considered most traditional.
Boon Oude Gueuze, Boon Oude Gueuze Mariage Parfait, De Cam Gueuze, De Cam/Drei Fonteinen Millennium Gueuze, Drie Fonteinen Oud Gueuze, Cantillon Gueuze, Hanssens Oude Gueuze, Lindemans Gueuze Cuvée René, Girardin Gueuze (Black Label), Mort Subite (Unfiltered) Gueuze, Oud Beersel Oude Gueuze
You can view the complete style details on the BJCP website. The 2008 style guide is obsolete but there is a similar 2015 style that you can view below...