envelopes active dry yeast or 2 tbsp active dry yeast
Yeast is a source of B vitamins (particularly thiamine and niacin) and contains selenium and protein. However, quantities used in typical recipes contribute negligibly to daily nutritional intake.
About
Active dry yeast (Saccharomyces cerevisiae) is a living microorganism cultured and processed for leavening baked goods and fermenting beverages. The yeast cells are harvested during fermentation, then dried and granulated to achieve dormancy, resulting in a shelf-stable product with approximately 95% dead cells and 5% live cells. Standard active dry yeast is sold in individual envelopes (typically 2.25 teaspoons or 7 grams) or in bulk, with a slightly coarser granule size than instant yeast and a faster hydration requirement.
Active dry yeast differs from instant yeast primarily in granule size and processing: instant varieties have smaller particles and require less hydration time. When rehydrated with warm liquid, dormant yeast cells reactivate and begin metabolizing sugars, producing carbon dioxide gas and alcohol—the chemical reactions that leaven dough and create the characteristic flavors of fermented products.
Culinary Uses
Active dry yeast is the standard leavening agent for bread dough, sweet doughs, and pastries across virtually all bread-making traditions. It is bloomed (rehydrated) in warm water before incorporation into dough, though modern methods often allow direct mixing with dry ingredients. Beyond baking, active dry yeast is essential in brewing beer, fermenting wine, and producing spirits; it is also used in some sourdough starters and other fermented preparations. The fermentation process not only generates rise but also develops flavor complexity, crust color, and crumb structure.