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
National Brewing Company two companies would result in a monopoly, denied the merger. Merely three years later, Carling-National was sold to G. Heileman Brewing Company of La Crosse, Wisconsin and the former brewing facility of Brewer's Hill was closed. Stroh Brewery Company of Detroit, Michigan later bought over the rights from Heileman in 1996. National Bohemian beer has not been brewed in Baltimore since. As of today, the brewery has been converted to business and office spaces as a part of the Brewers Hill redevelopment project by Obrecht Commercial Real Estate. National Bohemian, now only “National” in name, is brewed in North Carolina