Baking sourdough bread in a conventional home oven can be a truly frustrating experience. The dry heat leads to a crust that seals over before full oven spring can be achieved. STEAM is essential in the first part of baking because it keeps the dough surface pliable, not only allowing maximum oven spring but also creating a beautiful, glossy, blistered crust. Here’s the technique I recommend for creating enough steam to sustain the expansion period