What does the term “hydration” mean in sourdough baking, e.g. a 75% hydration dough, and how does it affect the dough and bread?

Question

What does the term 'hydration' mean in sourdough baking? Understand how the percentage of water affects the dough's texture and final bread crumb.

Answer 1

Hydration in sourdough baking refers to the ratio of water to flour in a dough. A 75% hydration dough means there are 75 grams of water for every 100 grams of flour, impacting dough stickiness, fermentation speed, and the bread's crumb structure.

Detailed Explanation:

Hydration is a crucial element in sourdough baking, directly influencing the dough's characteristics and the final bread product. It's expressed as a percentage, calculated by dividing the weight of water by the weight of flour and multiplying by 100. For example:

* **75% Hydration:** If you use 100 grams of flour, you'd use 75 grams of water.* **80% Hydration:** If you use 100 grams of flour, you'd use 80 grams of water.

**How Hydration Affects Dough:**

1. **Stickiness:** Higher hydration doughs are stickier and more challenging to handle. This is because there's more free water in the dough, making it less cohesive.
2. **Fermentation:** Higher hydration can accelerate fermentation. The increased water content provides a better environment for the yeast and bacteria in the sourdough starter to thrive.
3. **Gluten Development:** Higher hydration allows for better gluten development. The water helps the gluten proteins align and form a strong network, leading to a more elastic and extensible dough.

**How Hydration Affects Bread:**

1. **Crumb Structure:** Higher hydration typically results in a more open and airy crumb structure with larger holes. This is because the increased water creates more steam during baking, which expands the dough.
2. **Crust:** Higher hydration can lead to a thinner and crispier crust. The extra water evaporates during baking, creating a drier surface that browns more easily.
3. **Moisture:** Higher hydration breads tend to be more moist and stay fresher for longer.

Pro Tip:

When working with high-hydration doughs, use wet hands and a wet work surface to prevent the dough from sticking excessively. This makes handling and shaping much easier.