Firstly, follow the instructions that came with the yeast!!!Then, make sure that the fermenting mash is at the correct temperature. The yeast becomes intolerant of alcohol at higher temperatures. At low temperatures, the fermentation will be exceedingly slow, or may even stop.Fermentation should be done in a primary fementer that seals with a rubber gasket and is fitted with an airlock. In the presence of oxygen, yeast will multiply rapidly but will produce very little alcohol. If oxygen is excluded, the yeast will convert the sugar into alcohol. So, if you want to make alcohol, don't peek! Don't open the lid until fermentation is complete