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
Christian views on alcohol gifts," including wine and ale. As the Pilgrim Fathers set out for America, they brought a considerable amount of alcohol with them for the voyage (more than 28,617 liters = 7,560 gallons, or 4 litres/person/day), and once settled, they served alcohol at "virtually all functions, including ordinations, funerals, and regular Sabbath meals." M. E. Lender summarizes the "colonists had assimilated alcohol use, based on Old World patterns, into their community lifestyles" and that "[l]ocal brewing began almost as soon as the colonists were safely ashore." Increase Mather, a prominent colonial clergyman and president of Harvard, expressed the common view in