90g spelt flour
700g white bread flour
400g ferment, 50% hydration
650g water
20g salt
spelt or white flour for dusting, plus a little fine semolina, for dusting the peels

Have ready two wicker bread-raising baskets or two bowls lined with baking cloths. You will also need two quite large wooden peels or upturned baking trays for transferring the loaves to the oven.

Combine the flours in your large mixing bowl. Add the ferment, ripping it into pieces and mixing into the flour at the same time.

Add the water and mix together, using your scraper. When everything starts to come together into a dough, use your scraper to turn it out onto your work surface (don't flour the surface first).

Start to work the dough. After about 10 minutes, sprinkle the salt over the top and continue to work until the dough is smooth, strong, and elastic, and comes away from your work surface cleanly.

Lightly flour your work surface, and then form the dough into a ball. Put back into your (lightly floured) mixing bowl, cover with a baking cloth and let it rest for 1 hour.

Lightly flour your work surface, turn out the dough with the help of your scraper, fold it shaping into a ball again, and put it back into your bowl. Let it rest for another hour.

Lightly flour your work surface, turn the dough out and divide into 2 equal pieces (about 900g each).

Form each piece into a ball.

Dust your bread-rising baskets or cloth-lined bowls really well with either spelt or white flour. (One of the characteristics or sourdough when it has been baked is the contrast of the dark burst against the white, floured crust, so you need to flour your baskets or bowls very well at this stage).

Put your balls of dough, seam-side up, into your floured baskets or bowls – the smooth side of the dough that is nesting in the bowl, covering itself in flour, will eventually become the top of your bread.

Now you need to let the dough rise for 16-18 hours. This needs to happen fairly slowly at this point, so leave it in a slightly cooler place than you would normally (17–18°C is the ideal temperature).

Preheat your oven to 250°C roughly 2 hours before you want to bake. Remember to put in your baking stones or pans to get hot, one on each shelf of your oven if you're going to bake both loaves at the same time. Lightly dust your wooden peels or upturned baking trays with fine semolina.

After about 16–18 hours, the dough should have doubled in size and be springy to the tough. If it hasn't risen enough, leave it for an hour or so longer.

Turn out each ball of dough onto a lightly floured wooden peel or flat baking tray so that the rounded side of each loaf is upwards. They should be coated in flour from the bread-rising baskets/bowls.

Slash the top of each loaf with a lame or sharp blade.

Open the oven door and quickly mist the inside of the oven with your water spray. Slide your loaves onto the hot baking stones or trays int he oven, and spray some more before quickly closing the oven door.

Set your timer for 5 minutes. After this time, turn the heat down to 220°C and bake for another 25 minutes (you might need to swap the trays around halfway through baking, to make sure they are evenly baked). They are ready when the crust, where it has burst open, is pronounced and dark golden brown. The bottom should also be dark golden brown and sound hollow if you tap it. If they aren't ready, turn the heat down to 210°C for another 10-15 minutes. Cool completely on a rack before eating.