1. Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved8
Lean Yeast Doughs: Sponges,
Pre-Ferments, and Sourdoughs
Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved

2. 8 Advantages of Sponge Mixing Method: Lean Yeast Doughs: Sponges,
Pre-Ferments, and Sourdoughs
Sponges and Other Yeast Pre-Ferments
Advantages of Sponge Mixing Method:
Shorter fermentation time.
Scheduling flexibility.
Increased flavor, developed by long fermentation.
Less yeast needed.
Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved

3. 8 Sponge Mixing Method: Lean Yeast Doughs: Sponges,
Pre-Ferments, and Sourdoughs
Sponges and Other Yeast Pre-Ferments
Sponge Mixing Method:
Combine all or part of liquid, all of yeast, and part of the flour.
Let ferment until double in bulk.
Fold (punch down) and add the rest of the flour and other ingredients.
Mix into a smooth dough.
Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved

4. Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved8
Lean Yeast Doughs: Sponges,
Pre-Ferments, and Sourdoughs
Yeast Pre-Ferments
Poolish: thin yeast tarter made with equal parts flour and water plus commercial yeast.
Biga: the Italian term for pre-ferment. It usually is a stiff pre-ferment and made with two times the quantity of yeast as a poolish.
Levain-levure: French term for yeast pre-ferment. (Levure means “yeast.” Levain means “sourdough.”)
Pâte Fermentée: a piece of fermented bread dough saved from a previous batch.
Mixed fermentation: using bothboth a pre-ferment and a fresh addition of yeast are for leavening.
Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved

5. Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved8
Lean Yeast Doughs: Sponges,
Pre-Ferments, and Sourdoughs
Autolyse
Autolyse: An extra step during mixing helps create good gluten structure.
First combine the flour and water and mix at low speed just until the flour is moistened and a dough is formed. Let stand 30 minutes.
During the autolyse, the flour hydrates fully.
Finish mixing into a dough.
Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved

6. Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved8
Lean Yeast Doughs: Sponges,
Pre-Ferments, and Sourdoughs
Sourdough Starters
A dough or batter that contains wild yeasts and bacteria.
It has a noticeable acidity as a result of fermentation.
The wild yeasts in sourdough starters are not the same as commercial yeasts.
Wild yeasts can tolerate and grow in higher levels of acidity.
Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved

7. 8 Lean Yeast Doughs: Sponges, Pre-Ferments, and Sourdoughs
Bacterial Fermentation
Sourdough starters contain bacteria as well as yeast. The most important bacteria are from the group Lactobaccilli.
Two kinds of acid are created by bacteria, lactic acid and acetic acid.
Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved

8. 8 Lean Yeast Doughs: Sponges, Pre-Ferments, and Sourdoughs
Refreshing the Starter
After the initial fermentation has begun, the starter must be refreshed or fed regularly so the yeasts and bacteria are nourished and will multiply until they are strong.
The basic procedure is to combine a portion of the fermenting starter with additional flour and water.
Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved

9. Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved8
Lean Yeast Doughs: Sponges,
Pre-Ferments, and Sourdoughs
Fermentation
Fermenting at lower temperatures extends the fermentation time and develops more flavor.
Sourdoughs ferment more slowly.
Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved

10. Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved8
Lean Yeast Doughs: Sponges,
Pre-Ferments, and Sourdoughs
Baking
Most sourdough breads are baked as “hearth breads.”
If baked on pans, perforated pans are best.
Steam should be injected for the first 15 minutes. Most lean hearth breads are best baked in a hot oven, 425° to 450°F (218° to 232°C).
Copyright © 2017 by John Wiley & Sons, Inc. All Rights Reserved