What is the function of water when making pastry?

1. Hydration: Water is essential for hydrating the flour and other dry ingredients in pastry. When water is added to flour, it forms gluten, which gives pastry its structure and elasticity. The right amount of water will result in a dough that is easy to handle and roll out, without being too sticky or crumbly.

2. Development of Gluten: As mentioned above, water helps develop gluten in the flour. Gluten is a protein that forms when flour is mixed with water and worked, either by kneading or mixing. Gluten gives pastry its elasticity and strength, allowing it to hold its shape and rise during baking.

3. Temperature Control: Water also plays a role in controlling the temperature of the pastry dough. In many pastry recipes, cold water or ice water is used to keep the dough cool and prevent it from becoming too warm and sticky. This is especially important for pastries that require precise temperatures for the best results, such as puff pastry and choux pastry.

4. Dissolving Ingredients: Water is used to dissolve other ingredients in pastry, such as sugar, salt, and yeast. Dissolving these ingredients in water ensures they are evenly distributed throughout the dough, contributing to the overall flavor and texture of the pastry.

5. Steam Production: During baking, water turns into steam, which helps create flaky layers in pastry. The steam expands inside the dough, creating air pockets and causing the pastry to rise and puff up. This is particularly important in pastries like croissants and puff pastry, where the layers are a key characteristic.