pkgs dry yeast - pour in 3½ cups of warm water and stir 200 strong strokes until blended
Dry yeast is a good source of B vitamins, particularly thiamine and niacin, and contains some protein and minerals including selenium and chromium, though yeast is typically used in quantities too small to contribute significantly to daily nutritional intake.
About
Dry yeast is a dormant form of Saccharomyces cerevisiae, a single-celled fungus used as a leavening agent in baking and fermentation. Commercial dry yeast is produced by cultivating yeast cells and then drying them through spray-drying or drum-drying processes to remove approximately 93% of their water content, resulting in a shelf-stable powder that can remain viable for months to years when stored in cool, dry conditions.
The yeast cells remain metabolically inactive until rehydrated in warm liquid, at which point they resume fermentation, producing carbon dioxide gas that leavens dough and contributes to flavor development through the production of alcohols and organic acids. Dry yeast is available in several forms with differing activation speeds and cell concentrations.
Culinary Uses
Dry yeast is the primary leavening agent in bread baking, contributing to the rise of yeasted doughs and enriched doughs used in breads, rolls, pastries, and sweet applications. It is also used in the fermentation of beverages such as beer and wine, and in some culinary fermentation processes. In bread baking, yeast is typically rehydrated in warm water (105-110°F / 40-43°C) before mixing into dough, allowing for better distribution and activation. The rehydration step, sometimes called "blooming" or "proofing," ensures the yeast is alive and active before incorporation, which is particularly important for recipes with large quantities or longer fermentation times.