100 g sourdough starter

300 ml tepid water

500 g strong flour, any sort

25 ml tepid water

10 g salt

Cornflour, for dusting the proving basket

{“Extra starter refresh ingredients, if needed” => “150 g starter, 150 ml tepid water and 150 g strong flour”}

Keep the sourdough starter, or mother, in a lidded bowl in the fridge until you need it.

If you do not use the starter within a week, refresh it by taking 150 g out of the mix and putting it in a bowl. Add 150 ml tepid water and 150 g strong flour, then stir. It should have a thick American pancake consistency.

Throw away the surplus mix. Leave the refreshed starter at room temperature until you can see bubbles forming, approximately 3 hours, then return it to the fridge.

To make the loaf, stir 100 g starter, 300 ml tepid water and 500 g strong flour together with a rigid spoon. It will be very thick and dry, but blend everything as best you can. Cover the bowl with cling film and leave at room temperature for 1 hour.

Add 25 ml tepid water and 10 g salt to the dough and stir with a rigid spoon until all of the water has been integrated.

Cover and leave for 1 hour, stirring at 15 minute intervals. It does not have to be an energetic stir; just fold the dough 3-4 times.

After that hour, no more stirring is required. Let the dough sit for another 2 hours.

Gently decant the dough into a sourdough proving basket thoroughly covered in cornflour. A bowl lined with a tea towel may work if you do not have a proving basket, but a proving basket is more reliable.

Leave in the fridge overnight, or for 3-4 hours at room temperature, covered with a tea towel.

If the dough has been in the fridge, remove it while the oven preheats.

Preheat the oven to 200 °C fan. Ideally, if you have a fan and bottom heat combination, use this. Put a baking tray on the bottom shelf and a roasting pan half full of hot tap water on the top shelf. After about half an hour the water should be boiling and you will have a steam oven.

Remove the tray and immediately, but gently, tip the dough into the centre of the tray. Score a cross very lightly on top with a sharp knife.

Put in the oven on the bottom shelf and bake for 30 minutes. For your first attempt, put a probe into the centre of the loaf after 30 minutes. As long as it reads above 95 °C it will be cooked; if not, leave it for longer.

Cool on a rack.