Why is my sourdough flat? The usual causes and what to change

A flat sourdough nearly always comes down to one of four things: the starter wasn't ready, the dough proved for too long or not long enough, there was more water than you can handle yet, or the shaping was too loose. The crumb inside the loaf usually tells you which.

The starter wasn't ready

If your starter doesn't double in size within about four to eight hours of a feed at room temperature, it isn't strong enough to raise a loaf. The bread comes out low and dense, with a tight crumb all the way through.

Feed it once or twice a day at room temperature for a few days before you bake, and use it when it's at its highest point, domed and full of bubbles. Our post on looking after a sourdough starter has more on getting it lively again.

It proved for too long

Over-proved dough spreads as soon as you turn it out, sometimes sinks when you score it, and smells sharply sour. The baked loaf is wide and low with a pale crust.

Try the poke test before baking. Press a floured finger into the dough. If the dent springs back slowly and leaves a small mark, it's ready. If it stays put, it's gone too far. Next time, shorten the bulk ferment or move the final prove into the fridge, where it slows right down.

It didn't prove for long enough

Under-proved dough gives a different flat loaf: dense in the middle, a few big tunnels just under the crust, and often a split down one side where it burst open in the oven.

Give the bulk ferment more time, or find a warmer spot. By the end of it the dough should have grown by around half, feel airy and wobbly, and show bubbles at the sides of the bowl. Times in a recipe are only a guide, because a cold kitchen can add hours.

There was too much water

Wet doughs make big, open holes, which is why recipes online push the water up. They're also much harder to shape, and a beginner's wet dough often slumps across the tray. Take the water down by 25 to 50 grams per 500 grams of flour until the dough holds its shape, then add it back a little at a time as your hands get used to it.

The shaping was too loose

A loaf holds its height because shaping builds tension across the surface. If the outside of your shaped dough feels slack, it'll spread. Shape on a lightly floured or unfloured patch of the worktop so the dough grips as you drag it towards you, and prove it in a floured basket or a bowl lined with a floured tea towel so it keeps its shape.

The oven wasn't hot enough

Sourdough needs a hard blast of heat to rise in the first few minutes. Preheat a lidded cast iron pot in the oven at its hottest, around 240 to 250°C, for 45 minutes. Bake with the lid on for 20 minutes to trap the steam, then lid off until the crust is a deep brown.

Learn it with your hands in the dough

It's much easier to recognise properly proved dough once someone has shown you what it feels like. Fixing the common problems is part of every sourdough workshop in Mears Ashby.