With your active starter, make leaven 24 hours before you want your bread ready. To do this, take 60g of starter, 100g warm water and 100g flour. Leave for 8-12 hours.
To make your dough, use 150g leaven, 275g warm water, 400g flour, 25g wholemeal, 10g salt. mix well and leave for an hour.
1. Then stretch the dough and fold into the middle. Leave for 45 mins.
2. Repeat the stretch and fold and leave for 45 mins.
3. Finally stretch and fold again. Leave for about 20mins so that your total proving time is 3 - 3.5 hours.
4. Remove dough onto floured surface and stretch the dough and fold it into a circular shape, this is your underside so then flip over and leave for 20 mins.
5. Then flip over again and stretch and fold your dough again into the middle. Flip over and then tighten the surface of the dough by turning the dough and stretching the 'skin' underneath. Then put the dough upside down in a floured proving basket or lined bowl. Leave at room temperature for an hour, then in the fridge overnight.
6. The next morning, preheat oven with cast iron pot in to the highest temp.
7. When hot, remove bread from fridge, slash the top and cook in the pot for 25 mins.
8. Then, remove lid and bake for a further 8-10 mins.