Week 2: Lean dough, and what the oven does to it

Flour, water, salt and yeast taken seriously — autolyse, poolish, surface tension, and why the first ten minutes of the bake need steam

1 March 2027

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A baguette has nowhere to hide. No butter, no egg, no sugar, no milk — the same four ingredients as last week’s tin loaf, in almost the same proportions, and a completely different bread at the end of it. The difference is entirely in handling and heat, which is why this is the second week rather than the tenth.

Time as an ingredient

Bakers’ percentages describe a dough’s composition. They say nothing about when each thing arrives, and for a lean dough that is most of the recipe.

An autolyse is flour and water alone, mixed roughly and left for 20 to 60 minutes before the salt and yeast go in. Two things happen while you wait. The starch and protein finish absorbing water, which mixing would otherwise have to force; and gluten strands begin linking up on their own, so the dough reaches full development on a fraction of the mixing time. Salt is held back because it tightens gluten and slows the enzymes; yeast is held back because there is no reason to start fermentation before the dough can hold gas.

A poolish is a different use of time: equal weights of flour and water with a trace of yeast — around 0.1% of the preferment’s flour — left 12 to 16 hours at room temperature. It contributes flavour that no amount of bulk fermentation in a single afternoon will produce, and it makes the dough noticeably more extensible, which is what lets you roll a 350 g piece out to 45 cm without it snapping back.

Shaping builds a skin

The instinct when you pick up risen dough is to be gentle with the gas and rough with the shape. Reverse both. The gas you can spare; a baguette’s open, irregular crumb comes from large bubbles surviving shaping, and it survives better in dough handled decisively than in dough pawed at.

What you are actually making is a tensioned outer skin. Each fold-and-seal stretches that surface a little tighter, and the seam is where the tension terminates. Pre-shape, let the gluten relax for 20 minutes, then shape properly — shaping tight dough twice in a row just tears it.

A seam that is folded over but not pressed closed holds until the oven. Then the loaf expands, the weakest line gives first, and it opens along the bottom seam instead of where you scored it.

Scoring and steam are one system

Score at a shallow angle — 20 to 30 degrees, the blade almost lying along the loaf — about 5 mm deep, with each cut overlapping the next by a third. That angle leaves a flap of dough. As the loaf springs, the flap peels back and sets into a raised ridge: the grigne, or ear. A vertical cut has no flap to peel, so it just opens into a flat slot; a deep cut cuts through the tensioned skin you spent ten minutes building and the loaf slumps sideways.

Steam is what buys the time for any of that. Water condensing on the cool crust keeps the surface moist and stretchy for the first 10 minutes, so it goes on expanding while the interior is still heating. It also gelatinises the surface starch, which dries later into that thin glassy shell. Then you vent the oven, and the dry heat at 250 °C drives Maillard browning and caramelisation for colour and the snap.

Skip the steam and the surface dehydrates in the first two minutes. The crust sets while oven spring is still happening, the scores stay shut, and you get a pale, matt, slightly tough loaf that is smaller than it should have been.

Outline

Teaching team