The crust is the part of the loaf most bakers notice first and understand least. The colour, the crackle, the deep caramel smell coming out of the oven — those are chemistry, not luck. Specifically, they are the Maillard reaction: a chain of chemical events between amino acids and reducing sugars that produces hundreds of flavour compounds.

Understanding this is why steam matters in the first half of the bake, and why you remove it in the second half. The two stages of baking are addressing two entirely different problems: oven spring and crust development. You cannot optimise both simultaneously.

The panel is the last in the series of twelve. Between them, they cover the microbiology, the chemistry, and the technique behind sourdough. The data — the fermentation charts Francis has been building — will follow in a later section of the blog.