The brewers of Belgium have been more inventive than any others. They allow many different microbes to participate in the fermentation; they ferment some beers for years, either continuously or by restarting them; they flavor their beers with spices and herbs, and even re-ferment them with fresh fruits to make a hybrid beer and fruit wine. They generally used aged hops, which are less harmful to the unusual brewing microbes, less bitter, and higher in drying, slightly astringent, wine-like tannins.