Yeast: Types, Baking Uses, and Proofing Tips

Baker’s yeast is a single-celled fungus that converts sugars into carbon dioxide and alcohol, causing dough to rise. Common forms: **instant**, **active dry**, and **fresh (cake)** yeast. (Note: **nutritional yeast** is deactivated and used for flavor, not leavening.)

- Tiny usage amounts in dough; contributes modest **B vitamins** and **minerals** - **Active yeast** is alive; **nutritional yeast** (deactivated) is rich in B-vitamins (often fortified) but doesn’t leaven

- **Leavening & structure:** CO₂ stretches gluten network for open crumb - **Flavor development:** Fermentation creates **organic acids** and **aroma compounds** - **Dough handling:** Proper bulk fermentation improves extensibility and oven spring

- **Allergy/intolerance** to yeast is uncommon but possible - **Sensitivity to histamine/biogenic amines** in long ferments for some individuals - **Interactions:** Very rare—follow medical advice if on specific antifungals - **Sodium:** Packaged mixes may include salt—check the label

- **Instant yeast:** mix directly with flour; typical dose **0.5–1%** of flour weight - **Active dry:** **bloom** in lukewarm water (35–40°C) 5–10 min before mixing - **Fresh yeast:** crumble into dough; use ≈ **2–3×** the weight of instant - **Temps:** fermentation best at **24–28°C**; cold proof in fridge for flavor - **Salt & sugar:** keep salt away from direct yeast contact initially; sugar boosts early activity but too much slows yeast - **Storage:** keep sealed, cool, and dry; refrigerate/freeze opened yeast

Choosing the right yeast form and managing temperature, time, and dough salinity yields reliable rise, aroma, and crust—proof smart, bake better.