Over-kneading brioche dough results in a tough, dense bread due to excessive gluten development, which makes the dough difficult to shape and reduces its characteristic tenderness.
Brioche dough is enriched with a high proportion of butter and eggs, which naturally inhibits gluten development. Kneading is essential to develop enough gluten to provide structure, but overdoing it can be detrimental. When brioche dough is over-kneaded, the gluten strands become too strong and tightly wound. This leads to several problems:
Tough Texture: The excessive gluten creates a bread that is chewy and tough, rather than soft and tender.
Difficult Shaping: Over-kneaded dough becomes very elastic and resistant to shaping. It will constantly spring back, making it hard to achieve the desired form.
Reduced Volume: While some gluten development is necessary for proper rise, too much can hinder the dough's ability to expand fully during proofing and baking, resulting in a denser loaf.
Coarse Crumb: The crumb structure will be uneven and coarse, lacking the delicate, airy texture characteristic of well-made brioche.
It's important to note that brioche dough is often kneaded for a longer time than lean doughs, but the key is to monitor the dough's texture. It should be smooth, elastic, and slightly tacky, but not overly tight or resistant.
Use the windowpane test to check gluten development. Gently stretch a small piece of dough between your fingers. If you can stretch it thin enough to see light through it without tearing, the gluten development is sufficient. If it tears easily, continue kneading, but check frequently to avoid over-kneading.