Fresh Yeast (Lievito di Birra)
Fresh compressed baker's yeast used in Italian pizza dough and bread. Activates at 20–35°C, leavening dough through CO2 production during fermentation.
Nutrition per 100g
| Energy | 89 kcal |
| Protein | 11g |
| Carbohydrates | 9g |
| Fat | 1.7g |
| Fibre | 8g |
| Salt | 0.05g |
Fresh Yeast (Lievito di Birra)
Lievito di birra fresco (fresh baker's yeast) is compressed live yeast, sold in 25g cubes at Italian supermarkets. It is the traditional leavening agent for Neapolitan pizza dough, focaccia, and Italian bread.
Fresh vs Dry Yeast
Italian bakers almost universally use fresh yeast for pizza when available. The practical differences:
| Fresh Yeast | Dry Instant Yeast | |
|---|---|---|
| Form | Compressed cube | Granules |
| Storage | Refrigerated, 2–3 weeks | Room temperature, 1–2 years |
| Quantity for 500g flour | 7–10g | 3–5g |
| Price per kg | ~€7/kg | ~€35/kg |
| Price per recipe | ~€0.05 | ~€0.10 |
Dry instant yeast produces equivalent results in home baking contexts. For the recipe calculator, fresh yeast is used as the baseline (7g per recipe for 500g flour). The cost difference per recipe is minimal either way.
How Yeast Works in Pizza Dough
Fresh yeast contains Saccharomyces cerevisiae organisms that consume sugars in the flour and produce CO2 and alcohol. The CO2 creates gas bubbles, which are trapped by gluten strands as the dough ferments — this is what makes pizza dough light and airy.
Key variables:
- Temperature: Yeast is active between 20–35°C. Above 45°C, it dies. Cold fermentation (4–8°C, 12–48 hours) produces more complex flavour due to slower, more even fermentation.
- Salt: Salt regulates yeast activity. Always add salt separately from yeast — direct contact at full concentration can inhibit the yeast.
- Time: Longer fermentation (cold method) produces better texture and flavour than rapid room-temperature methods.
Cost Context
At Italian supermarkets (Q1 2025), fresh yeast 25g cubes retail at approximately €0.18 each, yielding €7.20/kg. A pizza recipe for 4 uses 7g, costing approximately €0.05 — a negligible contribution to total ingredient cost. Yeast is present for completeness in cost calculations.