pkg yeast; active

Active dry yeast is a form of Saccharomyces cerevisiae, a single-celled fungus used to leaven and ferment dough and other food products. The yeast cells are grown in a controlled fermentation process, then dried to reduce moisture content, killing the majority of the yeast while preserving viability in the remaining living cells. Unlike fresh yeast, which contains approximately 70% moisture, active dry yeast contains only 8-10% moisture and is composed of larger granules formed from dead yeast cells mixed with living cells and growth medium. The flavor profile includes mild malt notes and slight bitterness from the fermentation residue. A single package typically contains 2.25 teaspoons (7 grams) of yeast, sufficient to leaven approximately one pound of flour.

Active dry yeast is fundamental to breadmaking, particularly in artisan and home baking traditions across Europe and North America. It is used to ferment dough for loaves, rolls, bagels, and sweet dough applications such as brioche and cinnamon rolls. The ingredient also ferments beer, wine, and other beverages, and is employed in some savory dishes requiring slow fermentation. Active dry yeast requires rehydration in warm water before use (typically 105-110°F), which allows the dormant cells to awaken and begin metabolic activity. It produces visible bubbling and foam when properly activated, signaling readiness for mixing with flour. The fermentation time varies from 1 to 24 hours depending on temperature, dough composition, and desired flavor development.