Step 1

Mix the raw cacao powder and instant coffee together with the 380g of water and mix until it's all dissolved.

Step 2

Weigh out your sourdough starter and then add the water mixture from step 1 into a large ceramic or glass bowl. Mix the water and starter together briefly. Then add your flour and salt and mix together with the end of a wooden spoon. The dough will be fairly shaggy and only just brought together.Cover your bowl with cling film or a damp tea towel and let it sit for around 1 hour. It's ok if it's a little longer.

Step 3

Forming Up Your Dough:After the dough has been through autolyse, you need to bring it together into a ball. You'll notice that the dough is fully hydrated after soaking up all the liquid. It will be fairly sticky but as you bring it into a ball, it will become smoother and shinier.Work your way around the bowl, grabbing the dough from the outside and stretching it up and over itself until a smooth ball is formed. You shouldn't need more than 20-25 folds to form the ball, you might need less.

Step 4

Once the dough has formed into a smooth ball, pop the cling film back on and let it rest in the bowl for around 30 minutes.

Step 5

Stretching and Folding:Over the next few hours, you need to create some structure for you dough by stretching and folding. Aim to do around 4-6 sets of stretches and folds. For each set, stretch the dough up and over itself 4 times as you rotate the bowl. You'll find it gets easier to do at each set as the gluten in your dough develops.Around your second or third set of stretch and folds, you'll need to add your chocolate chips and walnuts. Don't worry if they aren't evenly distributed in the first set of stretch of folds you do with them - they will distribute over the next few sets.

Step 6

Bulk Ferment:Once you've finished your stretch and folds, place the cling film or damp tea towel back over your dough and let it rest and ferment.

Step 7

Shaping Your Dough:Once your dough has finished its bulk ferment, it's time to form it back into a ball and give it some shape and surface tension. You'll need to flour your counter top with some rice flour for this (I like to add some raw cacao powder to my rice flour for this recipe).Shape your dough into a boule or batard. I think this recipe works well as a boule.Once you're happy with the shape, place your dough into your banneton or bowl, ensuring that you've liberally floured whatever you are using.

Step 8

Cold Ferment:Now your dough is in it's shaping container, cover it loosely with a plastic bag or damp tea towel and place it into the fridge.Try to leave it for a minimum of 5 hours, up to a maximum of 36 hours. The longer you leave it, the better your bread will be.

Step 9

Getting Ready To Bake:Once you're ready to bake your sourdough, you'll need to preheat your oven to 230C/450F. Place your Dutch Oven into the oven when you turn it on so that it gets hot. Try to preheat for around 1 hour to ensure your oven is super hot - but you know your oven, so just adjust this time if you need to.Leave your dough in the fridge until the very last minute.

Step 10

Bake Your Sourdough:When your oven is at temperature, take your sourdough out of the fridge. Gently place it onto a piece of baking paper or parchment paper.Gently score your bread with a lame, clean razor blade or knife. A cross is sufficient, but you can get as artistic as you like.

Step 11

Carefully take your Dutch Oven out of the oven. Place the sourdough into the pot using the baking paper as a handle. Put the lid on and place into the hot oven. If you want you can spritz your dough with extra water before you put the lid on.

Step 12

BAKE TIME:Bake your sourdough for 30 minutes at 230C/450F lid on plus10 to 15 minutes at 210C/410 lid off

Step 13

Once the time has elapsed, remove your sourdough from your Dutch Oven. Turn off your oven and place the sourdough back into the oven, directly on your oven rack. Let it cool in here with the door ajar for 1-2 hours.This will ensure that it is completely cooked through and you don't have any doughy bits.