Wine and Cider Yeasts
Yeast is a very important ingredient in making alcoholic beverages like wine and cider. In fact, yeast distinguishes the difference between wine and grape juice. The yeast transforms sugar from the grapes to carbon dioxide and alcohol through the process of fermentation. The more sugar found in grapes the higher the alcohol level of the wine produced. The process of fermentation occurs in the absence of Oxygen.
In winemaking, the most commonly used yeast is the Saccharomyces cerevisiae which is favoured by commercial and home brewers because of its predictable fermentation capabilities. It also has high levels of sulfur dioxide and alcohol. Moreover, it can live in pH levels between 2.8 and 4.
Today, there are different types and strains of yeasts used in making wine and cider. Many manufacturers sell general purpose yeasts intended for making wine, beer, ale or champagne. Most of these yeasts are capable of fermenting grain and sugars at different temperatures. (more info below)