The method of brewing pursued in Belgium would seem the most unscientific known, still the Belgium beers are largely consumed in Europe. No yeast whatever is used, tut the wort is left to ferment of itself, as it were, standing in the vats at a low temperature, until fermentation is provoked by germs that have accidentally fallen into it, or which may have found their way in during the process of manufacture. The action is naturally very slow, requiring sometimes several years for its completion, and a considerable formation of acid takes place, which is a predominant constituent in this class of beers.