Can I use the yeast I buy in the supermarket or health food store to make beer or wine?

No. Bread yeast is specifically designed to make bread, beer yeast designed for beer and wine yeast for wine (although some types of beer use wine yeast). If you try to use one for the other, you will be disappointed with the results, and you most likely will not get what you wanted. In the worst case, you will have to throw out the whole batch. The brewer's yeast available in health food stores is a nutritional product, and will not ferment. In the early days of fermentation, the role of yeast was not known, and depended heavily on airborne yeasts (wild yeast). Therefore, the fermentation was a hit-or-miss type of process. Using a product designed for your process will give you the control over the process, rather than the other way around. ... more