What You Are Actually Making

Sourdough is simply flour and water left to ferment. Wild yeasts and bacteria already living on the flour and in your kitchen do the work that a packet of commercial yeast does, only more slowly and with far more flavour. The reward is a loaf with a blistered, crackling crust, a moist open crumb, and a gentle tang you cannot buy from a supermarket shelf. If you have ever stood in a French bakery at seven in the morning, that is the smell you are chasing.

The encouraging part for a beginner is that none of this demands special skill. It demands time, a warm corner of the kitchen, and the willingness to bake one or two mediocre loaves before something genuinely lovely appears.

Building a Starter That Actually Works

You need only two things: strong white bread flour and water. Tap water is fine in most of the UK, but if yours is heavily chlorinated, leave it in a jug overnight so the chlorine dissipates.

On day one, mix 50g flour with 50g water in a clean jar and stir until no dry patches remain. Cover loosely — a lid sitting slightly ajar is ideal, because the mixture needs to breathe. For the next seven to ten days, tip away half of the starter each day and feed the remainder with another 50g flour and 50g water.

What you are looking for:

• Days 1–3: a few bubbles, a faint sour smell, possibly a burst of activity that then dies down.
• Days 4–7: a steady rhythm of rising and falling a few hours after each feed.
• Days 8–10: it doubles in size within four to six hours of feeding, smells of yoghurt and apples, and passes the float test — a teaspoon dropped into water bobs on the surface.

Once it reaches that stage, keep it in the fridge and feed it once a week. Bring it out and give it two feeds before you bake.

The Dough: Three Ingredients, One Bowl

For a single 800g loaf you need 500g strong white bread flour, 350g water, 100g active starter and 10g fine sea salt. That is a hydration of 70 per cent, which is forgiving enough for a beginner to handle without the dough turning into a puddle.

Mix the flour and water first and leave it for 45 minutes. This rest, called an autolyse, hydrates the flour and begins developing gluten without any kneading at all. Then add the starter, squidge it through with your fingers, and finally the salt. You will feel the dough tighten almost immediately.

Folds, Not Kneading

Forget ten minutes of arm-aching kneading. Sourdough is built with folds, which strengthen the dough gently and keep all that precious gas inside.

Leave the dough in the bowl, covered, somewhere around 20–22°C. Every 30 minutes, wet your hand, lift one side of the dough up and fold it over the middle, rotate the bowl a quarter turn, and repeat four times. Do this four times in total, so the whole process takes about two hours. You will notice the dough becoming smoother, springier and less sticky with each set.

After the folds, leave it alone. This is the bulk fermentation, and it usually takes four to six hours at room temperature. It is done when the dough has risen by roughly half, looks domed at the edges, feels jiggly when you shake the bowl, and pulls away cleanly. In a cold kitchen this takes longer; in a heatwave, considerably less. Trust your eyes over the clock.

Shaping and the Cold Prove

Turn the dough onto a lightly floured surface. Shape it into a rough round by folding the edges into the centre, then leave it seam-side down for 20 minutes to relax. Now shape it properly: flip it over, fold the sides in, and roll it towards you to create tension across the top. This tight skin is what gives you a good rise in the oven.

Place it seam-side up in a floured banneton, or in a bowl lined with a tea towel dusted generously with rice flour or plain flour. Cover and put it in the fridge for 8 to 16 hours. This slow, cold prove develops flavour and makes the dough far easier to score.

The Bake

Preheat your oven to 240°C with a heavy cast-iron casserole or baking stone inside for at least 45 minutes. Sourdough needs fierce, trapped steam at the start, and a lidded pot provides exactly that.

Turn the cold dough out onto baking parchment, dust the top, and slash it once at a shallow angle with a sharp blade or a serrated knife. Lift it into the hot pot, put the lid on, and bake for 20 minutes. Remove the lid, drop the temperature to 220°C, and bake for a further 20 to 25 minutes until the crust is deep mahogany and the loaf sounds hollow when tapped underneath.

Then comes the hardest part: leave it on a wire rack for at least two hours before cutting. Slice it warm and the crumb will gum up, undoing all your patience. Wait, and you will be rewarded with a loaf worth every hour it took.