Yeast (Active Dry, Instant & Fresh)
A living microscopic fungus that ferments sugars, producing carbon dioxide gas and alcohol to rise bread dough.
1 Envelope Active Dry Yeast = 7g (2.25 Tsp) = 5g Instant Yeast = 15g Fresh Yeast
Yeast is a single-celled, living microscopic fungus (Saccharomyces cerevisiae) that serves as the primary biological leavener in bread making. During the fermentation process, yeast consumes simple sugars present in wheat flour, converting them into carbon dioxide gas and alcohol. The carbon dioxide bubbles become trapped within the elastic gluten network of the dough, causing it to stretch and rise. This process also develops complex organic acids that give bread its distinct yeasty aroma and flavor. Yeast is highly sensitive to temperature: it is dormant at cool refrigerator temperatures, active between 70°F and 95°F (21°C to 35°C), and dies instantly at temperatures above 138°F (59°C).
Yeast is available in three common forms: Active Dry (requires blooming in warm water), Instant/Rapid Rise (can be mixed directly into dry ingredients), and Fresh/Cake yeast (perishable, preferred by professional bakeries for slow rises). Converting between these forms requires precise weight adjustments, as their moisture levels and yeast cell densities vary.
Dissolving active dry yeast in water that is too hot (above 115°F/46°C). The heat kills the living yeast cells, preventing the dough from rising and resulting in a brick-like loaf.
In the US, 7g active dry yeast packets are standard. In the UK and Europe, instant yeast (often labeled as Easy Bake or Fast Action) is more common.
Essential for making yeast-leavened sandwich breads, artisan sourdoughs, bagels, brioche, croissants, and pizza doughs.
To replace active dry yeast with instant yeast, use 25% less instant yeast by weight. To substitute fresh yeast for active dry, multiply weight by 3.
Store unopened yeast in a cool pantry. Once opened, keep in an airtight container in the refrigerator for up to 4 months, or freeze for up to 1 year.