Brewing much studied, the preservative nature of the soft resins is not yet fully understood, though it has been observed that unless stored at a cool temperature, the preservative nature will decrease. Brewing is the sole major commercial use of hops. Yeast is the microorganism that is responsible for fermentation in beer. Yeast metabolises the sugars extracted from grains, which produces alcohol and carbon dioxide, and thereby turns wort into beer. In addition to fermenting the beer, yeast influences the character and flavour. The dominant types of yeast used to make beer are "Saccharomyces cerevisiae", known as ale yeast, and "Saccharomyces
Women in brewing chewing or malting, is unknown, women in both Japan and Taiwan in the modern age still engage in chewing rice to begin the fermentation process for making alcohol. In Chinese legend, Yi Di, wife of Yu the Great, is credited with making the first alcohol from rice grains. A female divine being in Ainu mythology known as Kamui Fuchi was the protector of brewing and brewers prayed to her and offered libations to ensure the warding off of evil spirits which might spoil the batch. In ancient Sumeria, brewing was the only profession that was "watched over by a female